Overclocking AMD CPUs with a locked multiplier: THG guide. All about the CPU-Z program Selecting the right components

If you overclock the Vishera processor, you will receive a set of different parameters in the UEFI/BIOS. Although compared to the Intel platform there are not so many of them. Below we have listed the most important of them.

"Vishera" voltages

• CPU Voltage

CPU core voltage – differs from one CPU to another depending on the VID/quality of the processor. This voltage is something most overclockers should pay attention to.

• CPU-NB Voltage

CPU northbridge voltage (not to be confused with chipset voltage); This part of the CPU operates in its own frequency and voltage domain. The CPU-NB frequency determines the speed of the memory controller and L3 cache. The CPU-NB component has a fairly significant impact on the overall system performance. At high frequencies, it is recommended to increase the CPU-NB voltage to increase system stability.

• CPU Voltage Offset

Most motherboards allow you to set an offset voltage that allows you to increase the voltage above the CPU VID voltage range. The offset voltage is added to the VID value and can affect overclocking in both positive and negative ways. The actual voltage is calculated as follows: CPU Voltage + Offset. Example: VID 1.350V + offset 0.100V = 1.45V actual voltage.

• NB Voltage

Chipset voltage. When overclocking by increasing the multiplier, it is not necessary to increase it.

• HT Voltage

If you want to overclock an AMD processor via the HT interface, you may need to increase this voltage.

• VDDQ

Memory voltage. Depends on the memory sticks used.

LLC/Loadline Calibration:

Prevents Vdroop effect (voltage drop under load). Unfortunately, not everyone has this setting. motherboard AMD.

The "" tab has only two groups, the first of which is General(general) is responsible for the basic characteristics of memory.

• Type- type random access memory, For example, DDR, DDR2, DDR3.
• Size- memory capacity, measured in megabytes.
• Channels #- number of memory channels. Used to determine the presence of multi-channel memory access.
• DC mode- dual-channel access mode. There are chipsets that can organize dual-channel access in different ways. From simple methods This symmetric(symmetrical) - when each channel contains identical memory modules, or assymetric when memory is used of different structure and/or volume. Asymmetric mode is supported by Intel chipsets starting with 915P and NVIDIA since Nforce2.
• NB Frequency- frequency of the memory controller. Starting with AMD K10 and Intel Nehalem, the built-in memory controller received separate clocking from the processor cores. This item indicates its frequency. For systems with a memory controller located in the chipset, this item is inactive, as can be observed.

Next group - Timings. Dedicated to memory timings, which characterize the time it takes for the memory to perform a certain typical operation.

• CAS# Latency (CL)- minimum time between issuing a read command ( CAS#) and the start of data transfer (read delay).
• RAS# to CAS# Delay (tRCD)- the time required to activate a bank line, or the minimum time between sending a signal to select a line ( RAS#) and a signal to select a column ( CAS#).
• RAS# Precharge (tRP)- time required to precharge the bank (precharge). In other words, the minimum time for closing a line, after which you can activate new line jar.
• Cycle Time (tRAS)- the minimum time the line is active, that is, the minimum time between the activation of the line (its opening) and the issuing of a precharge command (the beginning of closing the line).
• Bank Cycle Time (tRC)- minimum time between activation of lines of one bank. Is a combination of timings tRAS+tRP- the minimum time the line is active and the time it closes (after which you can open a new one).
• Command Rate (CR)- the time required for the controller to decode commands and addresses. Otherwise, the minimum time between issuing two commands. With a value of 1T, the command is recognized for 1 clock cycle, with 2T - 2 clock cycles, 3T - 3 clock cycles (currently only on RD600).
• DRAM Idle Timer- the number of clock cycles after which the memory controller is forced to close and precharge open page memory if it has not been accessed.
• Total CAS# (tRDRAM)- timing used by RDRAM memory. Defines the time in clock cycles of the minimum signal propagation cycle CAS# for the RDRAM channel. Includes delay CAS# and the delay of the RDRAM channel itself - tCAC+tRDLY.
• Row to Column (tRCD)- another RDRAM timing. Defines the minimum time between opening a row and an operation on a column in that row (same as RAS# to CAS#).

Of course, our readers know everything about overclocking. In fact, many CPU and GPU reviews wouldn't be complete without looking at overclocking potential.

If you consider yourself an enthusiast, forgive us a little basic information - we'll get into the technical details soon.

What is overclocking? At its core, the term is used to describe a component that operates at higher speeds than its specifications in order to increase performance. You can overclock different computer parts, including processor, memory and video card. And the level of overclocking can be completely different, from a simple increase in performance for inexpensive components to an increase in performance to an exorbitant level that is normally unattainable for products sold in retail.

In this guide, we'll focus on overclocking modern AMD processors to get the best performance possible given the cooling solution you choose.

Choosing the right components

The level of overclocking success depends very much on the system components. To begin with, you will need a processor with good overclocking potential, capable of operating at higher frequencies than the manufacturer normally specifies. AMD today sells several processors that have fairly good overclocking potential, and the line of processors " Black Edition" is aimed squarely at enthusiasts and overclockers due to its unlocked multiplier. We tested four processors from the company's different families to illustrate the overclocking process for each of them.

To overclock a processor, it is important that other components are also selected with this task in mind. Choosing a motherboard with an overclocking-friendly BIOS is quite critical.

We took a pair of Asus M3A78-T motherboards (790GX + 750SB), which not only provide a fairly large set of functions in the BIOS, including support for Advanced Clock Calibration (ACC), but also work perfectly with the AMD OverDrive utility, which is important for squeezing the most out of Phenom processors.

Choosing the right memory is also important if you want to achieve maximum performance after overclocking. Where possible, we recommend installing high-performance DDR2 memory that is capable of operating at frequencies above 1066 MHz on AM2+ motherboards with 45nm or 65nm Phenom processors that support DDR2-1066.

During overclocking, frequencies and voltages increase, which leads to increased heat generation. Therefore, it is better if your system uses a proprietary power supply that provides stable voltage levels and sufficient current to cope with the increased demands of an overclocked computer. A weak or outdated power supply, loaded to capacity, can ruin all the efforts of an overclocker.

Increasing frequencies, voltages and power consumption will, of course, lead to increased heat dissipation levels, so cooling the processor and case also greatly influences the overclocking results. We didn't want to achieve any overclocking or performance records with this article, so we took rather modest coolers priced at $20-25.

This guide is intended to help those users who are less experienced in overclocking processors, so that they can enjoy the performance benefits of overclocking their Phenom II, Phenom or Athlon X2. Let's hope that our advice will help novice overclockers in this difficult but interesting task.

Terminology

Various terms that often mean the same thing can confuse or even frighten the uninitiated user. So before we go directly to step by step guide, we'll look at the most commonly encountered terms related to overclocking.

Clock speeds

CPU frequency(CPU speed, CPU frequency, CPU clock speed): The frequency at which a computer's central processing unit (CPU) executes instructions (for example, 3000 MHz or 3.0 GHz). It is this frequency that we plan to increase in order to get a performance boost.

HyperTransport channel frequency: frequency of the interface between the CPU and the northbridge (for example, 1000, 1800 or 2000 MHz). Typically the frequency is equal to (but should not exceed) the northbridge frequency.

Northbridge frequency: frequency of the northbridge chip (for example, 1800 or 2000 MHz). For AM2+ processors, increasing the northbridge frequency will lead to increased memory controller performance and L3 frequency. The frequency must be no lower than the HyperTransport channel, but it can be increased significantly higher.

Memory frequency(DRAM frequency and memory speed): The frequency, measured in megahertz (MHz), at which the memory bus operates. This may include either a physical frequency, such as 200, 333, 400, and 533 MHz, or an effective frequency, such as DDR2-400, DDR2-667, DDR2-800, or DDR2-1066.

Base or reference frequency: By default it is 200 MHz. As can be seen from AM2+ processors, other frequencies are calculated from the base using multipliers and sometimes dividers.

Frequency calculation

Before we get into the frequency calculations, it's worth mentioning that most of our guide covers overclocking AM2+ processors such as the Phenom II, Phenom, or other K10-based Athlon 7xxx models. But we also wanted to cover the early AM2 Athlon X2 processors based on the K8 core, such as the 4xxx, 5xxx and 6xxx lines. Overclocking K8 processors has some differences, which we will mention below in our article.

Below are the basic formulas for calculating the above-mentioned frequencies of AM2+ processors.

• CPU clock speed = base frequency * CPU multiplier;
• northbridge frequency = base frequency * northbridge multiplier;
• HyperTransport channel frequency = base frequency * HyperTransport multiplier;
• memory frequency = base frequency * memory multiplier.

If we want to overclock the processor (increase its clock frequency), then we need to either increase the base frequency or increase the CPU multiplier. Let's take an example: the Phenom II X4 940 processor runs with a base frequency of 200 MHz and a CPU multiplier of 15x, which gives a CPU clock speed of 3000 MHz (200 * 15 = 3000).

We can overclock this processor to 3300 MHz by increasing the multiplier to 16.5 (200 * 16.5 = 3300) or raising the base frequency to 220 (220 * 15 = 3300).

But it should be remembered that the other frequencies listed above also depend on the base frequency, so raising it to 220 MHz will also increase (overclock) the frequencies of the north bridge, the HyperTransport channel, as well as the memory frequency. On the contrary, simply increasing the CPU multiplier will only increase the CPU clock speed of AM2+ processors. Below we'll look at simple multiplier overclocking using AMD's OverDrive utility, and then head into the BIOS for more complex base clock overclocking.

Depending on the motherboard manufacturer, BIOS options for processor and northbridge frequencies sometimes use not just a multiplier, but a ratio of FID (Frequency ID) and DID (Divisor ID). In this case, the formulas will be as follows.

• CPU clock speed = base frequency * FID (multiplier)/DID (divisor);
• Northbridge frequency = base frequency * NB FID (multiplier)/NB DID (divisor).

Keeping the DID at 1 will take you to the simple multiplier formula we discussed above, meaning you can increase CPU multipliers in 0.5 increments: 8.5, 9, 9.5, 10, etc. But if you set the DID to 2 or 4, you can increase the multiplier in smaller increments. To complicate matters, the values ​​may be specified as frequencies, such as 1800 MHz, or as multipliers, such as 9, and you may have to enter hexadecimal numbers. In any case, refer to the instructions for the motherboard or look on the Internet hexadecimal values to indicate different FIDs of the processor and northbridge.

There are other exceptions, for example, it may not be possible to set multipliers. Thus, in some cases, the memory frequency is set directly in the BIOS: DDR2-400, DDR2-533, DDR2-800 or DDR2-1066 instead of selecting a memory multiplier or divider. In addition, the frequencies of the northbridge and HyperTransport channel can also be set directly, and not through a multiplier. In general, we don't recommend worrying too much about these differences, but we recommend returning to this part of the article if the need arises.

Test hardware and BIOS settings

Processors

• AMD Phenom II X4 940 Black Edition (45 nm, Quad-Core, Deneb, AM2+)
• AMD Phenom X4 9950 Black Edition (65 nm, Quad-Core, Agena, AM2+)
• AMD Athlon X2 7750 Black Edition (65 nm, Dual-Core, Kuma, AM2+)
• AMD Athlon 64 X2 5400+ Black Edition (65 nm, Dual Core, Brisbane, AM2)

Memory

• 4 GB (2*2 GB) Patriot PC2-6400 (4-4-4-12)
• 4 GB (2*2 GB) G.Skill Pi Black PC2-6400 (4-4-4-12)

Video cards

• AMD Radeon HD 4870 X2
• AMD Radeon HD 4850

Cooler

• Arctic Cooling Freezer 64 Pro
• Xigmatek HDT-S963

Motherboard

• Asus M3A78-T (790GX+750SB)

power unit

• Antec NeoPower 650 W
• Antec True Power Trio 650W

Useful utilities.

• AMD OverDrive: overclocking utility;
• CPU-Z: system information utility;
• Prime95: stability test;
• Memtest86: memory test (bootable CD).

Hardware monitoring: Hardware Monitor, Core Temp, Asus Probe II, other utilities included with the motherboard.

Performance testing: W Prime, Super Pi Mod, Cinebench, 3DMark 2006 CPU test, 3DMark Vantage CPU test

• Manually configure Memory Timings;
• Windows power plan: High Performance.

Remember that you are exceeding the manufacturer's specifications. Overclocking is done at your own risk. Most hardware manufacturers, including AMD, do not provide a warranty against damage caused by overclocking, even if you use AMD's utility. THG.ru or the author are not responsible for damage that may occur during overclocking.

Introducing AMD OverDrive

AMD OverDrive is a powerful all-in-one overclocking, monitoring and testing utility designed for motherboards based on the AMD 700 series chipset. Many overclockers do not like to use a software utility under operating system, so they prefer to change the values ​​directly in the BIOS. I also usually avoid utilities that come with motherboards. But after testing the latest versions of the AMD OverDrive utility on our systems, it became clear that the utility is quite valuable.

We'll start by taking a look at the AMD OverDrive utility menu, highlighting interesting features as well as unlocking the advanced features we'll need. After launching the OverDrive utility, you are greeted with a warning message, clearly stating that you are using the utility at your own risk.

When you agree, pressing the "OK" key will take you to the "Basic System Information" tab, which displays information about the CPU and memory.

The "Diagram" tab displays a chipset diagram. If you click on a component, more will be displayed detailed information about him.

The "Status Monitor" tab is very useful during overclocking, as it allows you to monitor the processor clock speed, multiplier, voltage, temperature and load level.

If you click on the "Performance Control" tab in the "Novice" mode, you will get a simple engine that allows you to change the PCI Express (PCIe) frequency.

To unlock advanced frequency settings, go to the "Preference/Settings" tab and select "Advanced Mode".

After selecting the "Advanced" mode, the "Novice" tab was replaced by the "Clock/Voltage" tab for overclocking.

The "Memory" tab displays a lot of information about memory and allows you to configure delays.

There's even a built-in test to quickly evaluate performance and compare it with previous values.

The utility also contains tests that load the system to check the stability of operation.

The last tab "Auto Clock" allows you to perform automatic overclocking. It takes a lot of time, and all the excitement is lost, so we didn’t experiment with this function.

Now that you're familiar with AMD's OverDrive utility and have set it to Advanced mode, let's move on to overclocking.

Overclocking via multiplier

With the 790GX motherboard and Black Edition processors we used, overclocking using AMD's OverDrive utility is fairly easy. If your processor is not a Black Edition processor, you will not be able to increase the multiplier.

Let's take a look at the stock operating mode of our Phenom II X4 940 processor. The motherboard base frequency varies from 200.5 to 200.6 MHz for our system, which gives a core frequency between 3007 and 3008 MHz.

It’s useful to run some performance tests at the stock clock speed, so that you can then compare the results of an overclocked system with them (you can use the tests and utilities we suggested above). Performance tests allow you to measure performance gains and losses after changing settings.

To overclock a Black Edition processor, check the "Select All Cores" checkbox on the "Clock/Voltage" tab, then start increasing the CPU multiplier in small steps. By the way, if you don’t check this box, you can overclock the processor cores individually. As you overclock, be sure to keep an eye on temperatures and constantly run stability tests. Additionally, we recommend making notes regarding each change where you describe the results.

Since we were expecting a solid boost from our Deneb processor, we skipped the 15.5x multiplier and went straight to the 16x multiplier, which gave the CPU core clock at 3200 MHz. With a base frequency of 200 MHz, each increase in the multiplier by 1 gives an increase in clock frequency of 200 MHz, and an increase in the multiplier by 0.5 - 100 MHz, respectively. We performed stress tests after overclocking using the AOD stability test and the Small FFT Prime95 test.

After running Prime 95 stress tests for 15 minutes without a single error, we decided to further increase the multiplier. Accordingly, the next multiplier of 16.5 gave a frequency of 3300 MHz. And at this core frequency, our Phenom II passed through stability tests without any problems.

A multiplier of 17 gives a clock speed of 3400 MHz, and again stability tests were completed without a single error.

At 3.5 GHz (17.5*200) we successfully completed a one-hour stability test under AOD, but after about eight minutes in the heavier Prime95 application we got " blue screen" and the system rebooted. We were able to run all the performance tests at these settings without crashing, but we still wanted our system to go through the 30-60 minute Prime95 test without crashing. Therefore, the maximum overclock level for our processor at stock voltage is 1.35 V is between 3.4 and 3.5 GHz. If you do not want to increase the voltage, then you can stop there. Or you can try to find the maximum stable CPU frequency at a given voltage, increasing the base frequency in steps of one megahertz, which is for. a multiplier of 17 will give 17 MHz at each step.

If you don’t mind raising the voltage, then it is better to do this in small increments of 0.025-0.05 V, while you need to monitor the temperatures. Our CPU temperatures remained low, and we began to gradually increase the CPU voltage, with a small increase to 1.375 V resulting in Prime95 tests running at 3.5 GHz completely stable.

Stable operation with a multiplier of 18 at 3.6 GHz required a voltage of 1,400 V. To maintain stability at 3.7 GHz, a voltage of 1.4875 V was required, which is more than the AOD allows to set by default. Not every system will be able to provide sufficient cooling at this voltage. To increase the default AOD limit, you should edit the AOD .xml parameters file in Notepad, increasing the limit to 1.55 V.

We had to raise the voltage to 1,500 V to get the system to work stably in the 3.8 GHz tests with a multiplier of 18, but even raising it to 1.55 V did not lead to stable operation of the Prime95 stress test. The core temperature during Prime95 tests was somewhere in the region of 55 degrees Celsius, meaning we hardly needed better cooling.

We rolled back to the 3.7 GHz overclock, and the Prime95 test ran successfully for an hour, meaning system stability was verified. We then started increasing the base frequency in 1 MHz increments, with the maximum overclock level being 3765 MHz (203*18.5).

It is important to remember that the frequencies that can be obtained through overclocking, as well as the voltage values ​​​​for this, change from one processor sample to another, so in your case everything may be different. It is important to increase frequencies and voltages in small increments while performing stability tests and monitoring temperatures throughout the process. With these CPU models, increasing the voltage does not always help, and processors may even become unstable if the voltage is increased too much. Sometimes for better overclocking it is enough to simply strengthen the cooling system. For optimal results, we recommend keeping the CPU core temperature under load below 50 degrees Celsius.

Although we were unable to increase the processor frequency above 3765 MHz, there are still ways to further improve system performance. Increasing the frequency of the northbridge, for example, can have a significant impact on application performance, since it increases the speed of the memory controller and L3 cache. The northbridge multiplier cannot be changed from the AOD utility, but this can be done in the BIOS.

The only way to increase the clock speed of the northbridge under AOD without rebooting is to experiment with clock frequency CPU with a low multiplier and a high base frequency. However, this will increase both the HyperTransport speed and the memory frequency. We'll look at this issue in more detail in our guide, but for now let me present the results of overclocking three other Black Edition processors.

The other two AM2+ processors are overclocked in exactly the same way as the Phenom II, with the exception of one more step - enabling Advanced Clock Calibration (ACC). The ACC function is only available on motherboards with AMD SB750 Southbridge, such as our ASUS model with the 790GX chipset. The ACC feature can be enabled in both AOD and BIOS, but both require a reboot.

For 45nm Phenom II processors, it is better to disable ACC as AMD states that this function already present in the Phenom II crystal. But with 65nm K10 Phenom and Athlon processors, it is better to set ACC to Auto, +2% or +4%, which can increase the maximum achievable processor frequency.

Standard frequencies.

Maximum multiplier

Maximum overclocking

The screenshots above show the overclocking of our Phenom X4 9950 at the stock frequency of 2.6 GHz with a 13x multiplier and a processor voltage of 1.25 V. The memory frequency is crossed out because it was set to DDR2-1066, and not to the DDR2-800 mode that we used for overclocking. The multiplier was increased to 15x, giving a 400 MHz overclock at stock voltage. The voltage was increased to 1.45V, then we tried ACC settings on Auto, +2%, and +4%, but the Prime95 could only last 12-15 minutes. Interestingly, with ACC in Auto mode, a 16.5x multiplier and a voltage of 1.425V, we were able to increase the base frequency to 208MHz, which gave a higher stable overclock.

Standard frequencies

Maximum overclocking without increasing voltage

Maximum overclocking without using ACC

Maximum overclocking

Our Athlon X2 7750 operates at a standard frequency of 2700 MHz and a voltage of 1.325 V. Without increasing the voltage, we were able to increase the multiplier to 16x, which gave a stable operating frequency of 3200 MHz. The system was also stable at 3300 MHz when we increased the voltage slightly to 1.35 V. With ACC disabled, we increased the processor voltage to 1.45 V in 0.025 V increments, but the system was not able to operate stably at the 17x multiplier. It crashed even before stress testing. Setting ACC for all cores to +2% allowed Prime95 to run for an hour at 1.425 V. The processor did not respond well to voltages above 1.425 V, so we were able to get a maximum stable clock of 3417 MHz.

The benefits of enabling ACC, as well as the results of overclocking in general, vary significantly from one processor to another. However, it’s still nice to have such an option at your disposal, and you can spend time fine-tuning the overclocking of each core. We didn't see any significant overclocking gains from enabling ACC on either processor, but we still recommend checking out our 790GX review where we took a closer look at ACC and where it made a more significant impact on the Phenom X4 9850's overclocking potential.

BIOS options

Our maternal Asus board M3A78-T has been flashed latest version A BIOS that contains support for new CPUs and also provides the best chance of successful overclocking.

First you need to log in Motherboard BIOS board (usually done by pressing the "Delete" key during the POST boot screen). Check your motherboard's manual to see how you can clear the CMOS (usually using a jumper) if the system fails the POST boot test. Remember that if this happens, all previously made changes such as time/date, shutdown graphics core, boot order, etc. will be lost. If you're new to BIOS setup, pay close attention to the changes you make and write down the initial settings if you can't remember them later.

Easy navigation BIOS menu is completely safe, so if you are new to overclocking, then do not be afraid of anything. But make sure you exit the BIOS without saving any changes you've made if you think you might accidentally mess something up. This is usually done by pressing the "Esc" key or the corresponding menu option.

Let's dive into BIOS Asus M3A78-T as an example. BIOS menus vary from one motherboard to another (and from one manufacturer to another), so use the manual to find the appropriate options in your model's BIOS. Also, remember that the available options vary greatly depending on your motherboard model and chipset.

In the main menu (Main) you can set the time and date, and the connected drives are also displayed there. If a menu item has a blue triangle on the left, you can go to a submenu. The "System Information" item, for example, allows you to view the BIOS version and date, processor brand, frequency and amount of installed RAM.

The "Advanced" menu consists of several nested submenus. The "CPU Configuration" item displays information about the processor and contains a number of options, some of which are best disabled for overclocking.

You will probably spend most of your time in the "Advanced" menu item "JumperFree Configuration". Manual setting important settings is ensured by switching the "AI Overclocking" item to the "Manual" mode. On other motherboards, these options will probably be located in a different menu.

Now we have access to the necessary multipliers that can be changed. Please note that in the BIOS the CPU multiplier changes in steps of 0.5, and the northbridge multiplier in steps of 1. And the HT channel frequency is indicated directly, and not through the multiplier. These options vary significantly between different motherboards; for some models they can be set via FID and DID, as we mentioned above.

In the "DRAM Timing Configuration" item you can set the memory frequency, be it DDR2-400, DDR2-533, DDR2-667, DDR2-800 or DDR2-1066, as shown in the photo. In this BIOS version you will not need to set the memory multiplier/divider. In the "DRAM Timing Mode" item you can set delays, either automatically or manually. Reducing latency can improve performance. However, if you do not have completely stable values ​​of memory latencies at different frequencies at hand, then during overclocking it is very reasonable to increase the latencies CL, tRDC, tRP, tRAS, tRC and CR. Additionally, you can get higher memory frequencies if you increase tRFC latencies to very high values ​​such as 127.5 or 135.

Later, all the "relaxed" delays can be returned back to squeeze out more performance. Reducing one latency per system run is time-consuming, but worth the effort to get maximum performance while maintaining stability. When your memory is operating outside of specifications, run a stability test with utilities such as Memtest86 bootable CD, as unstable memory performance can lead to data corruption, which is not desirable. With all that said, it is quite safe to give the motherboard the ability to adjust the latencies on its own (usually this will set fairly “relaxed” latencies) and focus on overclocking the CPU.

Advanced overclocking

In this case, the adjective “advanced” is not very appropriate, since, unlike the methods discussed above, we will present here overclocking through the BIOS by increasing the base frequency. The success of such overclocking depends on how well the components in your system can overclock, and to find the capabilities of each of them, we will go through them one by one. In principle, no one forces you to follow all the steps given, but finding the maximum for each component can ultimately lead to higher overclocking, since you will understand why you are running into one or another limit.

As we said above, some overclockers prefer direct overclocking through the BIOS, while others use AOD to save testing time by not having to reboot every time. The settings can then be manually entered into the BIOS and try to improve them even further. In principle, you can choose any method, since each has its own advantages and disadvantages.

Again, it would be a good idea to disable the Cool"n"Quiet and C1E, Spread Spectrum and automatic systems fan controls that reduce its rotation speed. We also turned off the "CPU Tweak" and "Virtualization" options for part of our tests, but did not find a noticeable effect on any of the processors. These features can be enabled later if required and you can check if they affect your system performance or the stability of your overclocking.

Finding the maximum base clock speed

Now we'll move on to the techniques that owners of non-Black Edition processors will have to follow to overclock them (they cannot increase the multiplier). Our first step is to find the maximum base frequency (bus frequency) at which the processor and motherboard can operate. You will quickly notice all the confusion in the naming of the various frequencies and multipliers, as we already mentioned above. For example, the reference clock in AOD is called "Bus Speed" in CPU-Z and "FSB Frequency" in this BIOS.

If you plan to overclock only through the BIOS, then you should lower the CPU multiplier, northbridge multiplier, HyperTransport multiplier and memory multiplier. In our BIOS, lowering the Northbridge multiplier automatically reduces the available HyperTransport channel frequencies to or below the resulting Northbridge frequency. The CPU multiplier can be left as standard and then lowered in AOD, which makes it possible to further increase the CPU frequency without rebooting.

For our Phenom X4 9950 processor, we selected an 8x multiplier in the AOD utility, since even a 300 MHz base frequency with such a multiplier will be lower than the standard CPU frequency. We then raised the base frequency from 200 MHz to 220 MHz, and then increased it in 10 MHz steps up to 260 MHz. We then moved to 5 MHz steps and increased the frequency to a maximum of 290 MHz. In principle, it is unlikely to increase this frequency to the limit of stability, so we could easily stop at 275 MHz, since it is unlikely that the northbridge will be able to operate at such a high frequency. Since we were overclocking the base clock in the AOD, we ran AOD stability tests for a few minutes to ensure the system was stable. If we did the same thing in the BIOS, simply being able to boot into Windows would probably be a good enough test, and then we'd run final stability tests at a high base clock to make sure.

Finding the maximum CPU frequency

Since we already reduced the multiplier in AOD, we know the maximum CPU multiplier and now we already know the maximum base frequency we can use. With the Black Edition processor we can experiment with any combination within these limits to find the maximum value of other frequencies, such as the northbridge frequency, the HyperTransport channel frequency and the memory frequency. On this moment We will continue the overclocking tests as if the CPU multiplier was locked at 13x. We will look for the maximum CPU frequency by increasing the bus frequency by 5 MHz at a time.

Whether overclocking via BIOS or via AOD, we can always go back to the base clock of 200 MHz and set the multiplier back to 13x, which will give a stock clock speed of 2600 MHz. By the way, the north bridge multiplier will still remain 4, which gives a frequency of 800 MHz, the HyperTransport channel will operate at 800 MHz, and the memory will operate at 200 MHz (DDR2-400). We will follow the same procedure of increasing the base frequency in small increments, performing stability tests each time. If necessary, we will increase the CPU voltage until we reach the maximum CPU frequency (by enabling ACC in parallel).

Maximum performance gain

Having found the maximum CPU frequency of our AMD processors, we have taken a significant step towards increasing system performance. But processor frequency is only part of overclocking. To get maximum performance, you can work on other frequencies. If you increase the voltage of the north bridge (NB VID in AMD OverDrive), then its frequency can be increased to 2400-2600 MHz and higher, and you will increase the speed of the memory controller and L3 cache. Increasing the frequency and reducing RAM latency can also have a positive effect on performance. Even the high-end DDR2-800 memory we used can be overclocked above 1066 MHz, increasing voltage and possibly reducing latency. HyperTransport channel frequency generally does not affect performance above 2000 MHz and can easily lead to instability, but it can also be overclocked. The PCIe frequency can also be slightly overclocked to around 110 MHz, which can also provide a potential performance boost.

As all mentioned frequencies slowly rise, stability and performance tests should be carried out. Setting up different parameters is a lengthy process and may be beyond the scope of our guide. But overclocking is always interesting, especially since you will get a significant performance boost.

Conclusion

Let's hope that all our readers who want to overclock an AMD processor now have a sufficient amount of information on hand. Now you can start overclocking using the AMD OverDrive utility or other methods. Remember that the results and exact sequence of actions vary from one system to another, so you should not blindly copy our settings. Use this manual only as a guide to help you discover the potential and limitations of your system for yourself. Take your time, don't increase your pitch, monitor temperatures, perform stability tests, and increase the voltage a little if necessary. Always carefully probe the limit of safe overclocking, since a sharp increase in frequency and voltage blindly is not only a wrong approach for successful overclocking, but it can also damage your hardware.

The last piece of advice: each motherboard model has its own characteristics, so it doesn’t hurt to familiarize yourself with the experiences of other owners of the same board before overclocking. Adviсe experienced users and enthusiasts who have tried this motherboard model at work, I will help you avoid pitfalls.

Addition

We tested another copy of the AMD Phenom II X4 940 Black Edition processor, provided by the Russian representative office of AMD. It ran successfully at 3.6 GHz when we increased the supply voltage to 1.488 V (CPUZ data). It looks like 3.6 GHz is the threshold for most CPUs when air cooled. We successfully overclocked the memory controller to 2.2 GHz.

BIOS menu of the P35 Platinum motherboard. All performance related functions except peripherals, system time, power management are located in the “Cell Menu”. Users who want to adjust the frequency of the processor, memory, or other devices (for example, graphics card bus and south bridge) can use this menu.

Remember that if you are not familiar with BIOS settings, to quickly complete all settings, it is recommended to perform the “Load Optimized Defaults” item, which will ensure normal operation of the system. Before overclocking, we recommend that users perform this step first and then make fine adjustments.

Cell Menu of P35 Platinum motherboard

All overclocking-related settings are located in the "Cell Menu" section, which includes:

• Intel EIST
• Adjust CPU FSB Frequency
• CPU Ratio CMOS Setting (setting the CPU frequency multiplication factor in CMOS)
• Advanced DRAM Configuration (special DRAM configuration)
• FSB/Memory Ratio (FSB/memory frequency ratio)
• PCIEx4 Speed ​​Controller (PCIEx4 speed control)
• Adjust PCIE Frequency
• Auto Disable DIMM/PCI Frequency ( automatic shutdown DIMM/PCI frequencies)
• CPU Voltage (CPU supply voltage)
• Memory Voltage
• VTT FSB Voltage
• NB Voltage (Northbridge voltage)
• SB I/O Power (South Bridge I/O Power)
• SB Core Power (South Bridge Core Power)
• Spread Spectrum (clock frequency spectrum limitation)

The user interface of the “Cell Menu” is very simple. Related functions are combined into groups. Users can compare parameter values ​​and make settings step by step.

Before overclocking, please install the functions" D.O.T. Control” and “Intel EIST” to “Disabled” (Default is Enabled). These settings will allow you to set custom values ​​for the processor supply voltage and system bus frequency. After disabling these functions, the option “ CPU Ratio CMOS Setting (setting the processor frequency multiplication factor in CMOS)” .

1. CPU frequency: After loading the optimal settings, this option will automatically show the CPU frequency. For example for a processor Intel Core 2 Duo E6850 will display “333 (MHz)”. Frequency setting can be done using the numeric keys or the “Page Up” and “Page Down” keys. When setting, the value displayed in gray “Adjusted CPU Frequency” will change in accordance with the set frequency.

2. CPU frequency multiplier: Depending on the nominal processor frequency, for example, 1333MHz, 1066MHz and 800MHz, the range of multiplier values ​​will be different.

3. Special DRAM configuration: This option is for setting the duration of the memory delay. The smaller its value, the higher the operating speed. However, the limit to its increase depends on the quality of the memory modules.

Advice: If you are using commercially available overclockable memory modules, we recommend that you go to "Cell Menu" > Advanced DRAM Configuration > Configure DRAM Timing by SPD, set this option to Disable, then you will see 9 additional user options that allow you to improve memory performance.

4. FSB/Memory Ratio (ratio of FSB and memory frequencies): This setting determines the relationship between FSB and memory frequencies. When set to “Auto”, the memory frequency will be equal to the processor frequency. When setting a custom value, please follow the 1:1.25 rule. For example, a processor with a frequency of 1333MHz and DDR2-800 memory. Then 1333MHz / 4 x 1.25 x 2 = 833MHz and the DDR2 frequency will be 833MHz.

5. Adjust PCIE Frequency: Typically, PCI Express bus clock speed is not directly related to overclocking; however, fine tuning it can also help with overclocking. (The default value is 100. It is not recommended to set this value above 120 as it may damage the graphics card.)

6. CPU Voltage (CPU supply voltage): This point plays a vital role in overclocking, however, due to the complexity of the relationships, it is not so easy to select it best setting. We recommend that users perform this setting with caution as an incorrect value may cause processor failure. In our experience, when using a good fan, there is no need to set this value to the limit value. For example, for Core processor 2 Duo E6850, it is recommended to set the supply voltage to 1.45~1.5V.

7. Memory Voltage: Since the memory is controlled by the Northbridge, the memory supply voltage should be increased simultaneously with the supply voltage of the main components. Of course, the limit of this increase depends on the quality of the memory modules.

8. VTT FSB Voltage (VTT FSB supply voltage): To ensure that all main components of the system have similar operating voltages, the supply voltage VTT FSB must also be increased. This value should not be too high to avoid unwanted effects.

9. NB Voltage (Northbridge supply voltage): The Northbridge plays a vital role in acceleration. Maintaining the stability of the processor, memory and graphics card can be achieved by increasing this voltage. We recommend that users fine-tune this setting.

10. SB I/O Power: Southbridge controls the connection peripheral devices and expansion cards, which play a more important role on new platforms from Intel. The default voltage value for the ICH9R is 1.5V, which determines the I/O voltage setting for peripheral devices. We recommend increasing the voltage to 1.7~1.8V, which will increase the stability of the connection between the North and South bridges, and also help overclocking.

11. SB Core Power (South Bridge Core Voltage): Previously, the Southbridge was ignored during overclocking, however, with increasing supply voltage it improves performance.

It should be remembered that MSI highlights settings in different colors: gray indicates default settings, white indicates safe values, and dangerous values ​​are highlighted in red.

Adviсe: MSI Warns: Check your fan speed frequently. Good cooling plays a decisive role during overclocking.

System MSI board The P35 Diamond is a high-end model based on the Intel P35 platform, which not only contains the latest hardware, but also has overclocking potential. Everyone knows that BIOS is the soul of the motherboard, which determines its functionality and performance.

Below is the BIOS setup menu for the P35 Diamond motherboard. All performance-related functions, with the exception of peripherals, system time, power management, are located in the "Cell Menu" section. Those who want to adjust the frequency of the processor, memory or other devices (for example, graphics card bus and South Bridge) can use this menu.

Attention: Overclocking performance depends on environmental conditions, so we cannot guarantee that the following settings will work on every motherboard.

Remember, if you are not familiar with BIOS setup, it is recommended to use the "Load Optimized Defaults" option to quickly complete the setup and ensure correct work systems. Before overclocking, we recommend that users first boot the system with "Load Optimized Defaults" and only then perform fine tuning.

Cell Menu section of the P35 Diamond motherboard

All settings related to overclocking are located in the "Cell Menu" section. These include:

D.O.T. control (dynamic overclocking technology control)

Intel EIST (Enhanced Intel SpeedStep® Technology)

Adjust CPU FSB Frequency

CPU Ratio CMOS Setting (setting the processor frequency multiplier)

Advanced DRAM Configuration (special dynamic memory settings)

FSB/Memory Ratio (ratio of FSB and memory frequencies)

PCIEx4 Speed ​​Controller (PCIEx4 speed control)

Adjust PCIE Frequency (PCIE bus frequency)

Auto Disable DIMM/PCI Frequency (automatically disable DIMM/PCI clock frequency)

CPU Voltage (CPU supply voltage)

Memory Voltage

VTT FSB Voltage (VTT FSB supply voltage)

NB Voltage (North Bridge supply voltage)

SB I/O Power (South Bridge input/output power)

SB Core Power (South Bridge Core Power)

Spread Spectrum (clock frequency spectrum limitation)

The user interface of the "Cell Menu" section is very simple and groups similar functions; Users can match similar functions and make settings step by step.

Before overclocking, set the "D.O.T. Control" and "Intel EIST" functions to Disabled (enabled by default). These features must be disabled to allow custom processor and system bus voltages to be set. After completing these settings, the "CPU Ratio CMOS Setting" option will appear.

Adjust CPU FSB Frequency:
After loading the optimized settings, this function will automatically detect and display the CPU frequency. For example, for an Intel Core 2 Duo E6850 processor, the value "333 (MHz)" will be shown here. Frequency setting can be done using the number keys or the "Page Up" and "Page Down" keys. During the adjustment process, the value shown in gray "Adjusted CPU Frequency" will change according to the set frequency.




CPU Ratio CMOS Setting (setting the processor frequency multiplier):
Depending on the nominal frequency of the processor used, for example, 1333MHz, 1066MHz and 800MHz, the range of multipliers will be different. Usually the frequency is reduced to a minimum, which increases stability and ensures successful overclocking.




Advanced DRAM Configuration (special DRAM settings):
This item is intended to configure delays in the memory operating cycle. The lower the corresponding value, the higher the speed. However, the limit depends on the quality of the memory modules used.

Advice:
If you are using conventional overclockable memory modules available on the market, we recommend that you select Cell Menu > Advanced DRAM Configuration > Configure DRAM Timing by SPD and set the latter to Disable. . Next, 9 additional items will appear that will enable users to achieve better memory performance.



FSB/Memory Ratio (ratio of FSB and memory frequencies):
This setting determines the relationship between FSB and memory frequencies. If it is set to "Auto", the memory frequency will be equal to the processor FSB frequency. If it is specified by the user, follow the rule 1:1.25. For example, a 1333MHz processor with DDR2-800 memory, then 1333MHz / 4 x 1.25 x 2 = 833MHz. The DDR2 memory frequency will be 833MHz.




Advice:
To meet the wishes of overclocking enthusiasts, MSI has created a special mode in the "Cell Menu" - "Power User mode". Just press "F4" and the hidden menu will appear. The "Power User mode" menu items are focused on memory settings and include the SCOMP and ODT values.









Adjust PCIE Frequency:
Typically, PCI Express bus speed does not have a direct relationship with overclocking; however, fine-tuning it will also help with overclocking. (The default setting is 100, it is not recommended to increase it beyond 120 as it may damage the graphics card.)


CPU Voltage (CPU supply voltage):
This point is critical for overclocking, but due to the complexity of the relationships, finding the best setting is not easy. We recommend that users set this value with caution, as incorrect settings may damage the processor. According to our experience, if you have a good fan, there is no need to set the CPU voltage limit. For example, for the Intel Core 2 Duo E6850 processor, it is recommended to set the voltage in the range of 1.45~1.5V.


Advice:
Motherboard P35 Diamond uses DDR3 memory modules. According to the JEDEC definition of DDR3, its frequency range is between 800 and 1600 MHz. The standard values ​​are 800, 1066, 1333 and 1600MHz. Therefore, when installing some special DDR3 modules, we recommend that you set the minimum FSB/memory frequency ratio, and fine-tune the memory supply voltage to achieve success.

VTT FSB Voltage:
To provide similar supply voltages to all main devices, the VTT FSB voltage must also be increased. The increase should not be large so as not to cause a negative effect.


NB Voltage (North Bridge supply voltage):
The Northbridge plays a decisive role in overclocking, as it is important for maintaining the stability of the processor, memory and graphics card. This is achieved by increasing its supply voltage. We recommend that users fine-tune this setting.


SB I/O Power (South Bridge input/output power):
The South Bridge controls the connection of peripheral devices and expansion cards, which Lately are playing an increasingly important role on the Intel platform. The ICH9R's standard supply voltage is 1.5V, which determines the voltage setting for I/O devices. We recommend increasing the voltage to 1.7~1.8V, which will increase the stability of the joint operation of the North and South Bridges, and also help overclocking.


SB Core Power (South Bridge Core Power):
Previously, the South Bridge was ignored during overclocking, but with increasing supply voltage it increases performance.

In addition, remember that MSI in the supply voltage settings highlights different values ​​in different colors: gray corresponds to the standard value, white means a safe value, and a dangerous value is highlighted in red.

Adviсe:
MSI warns you to check fan speed and temperature frequently. Good cooling plays a decisive role during overclocking.

Attention:
The P35 Diamond is a powerful motherboard that provides a full range of overclocking features and system protection. If three unsuccessful overclocks in a row, the system will automatically set the standard BIOS settings for reliable system booting. Before overclocking, make sure that each component is able to withstand its mode. MSI is not responsible for any damage caused by failed overclocking. This article is for informational purposes only.

Once all settings are set, we recommend saving them using the "User Settings" function in the BIOS menu, which makes loading settings easier and also allows you to set default settings if overclocking fails. The user can save two sets of settings and select the required one.

In the User Settings section, "Press Enter" to save the BIOS settings.

If overclocking fails, users still have the option to enter the User Setting section to set more appropriate parameters to restore normal operation.

How to overclock P35 Diamond motherboard

Earlier than expected, the Intel platform entered the era of DDR3 memory. DDR3 memory has lower operating voltage, heat dissipation and higher clock speed. It has better overclocking efficiency than DDR2. However, the chipset and memory modules still do not have an overclocking environment, and this limits the potential of DDR3.

The MSI P35 Diamond motherboard from MSI comes with DDR3 memory and looks very similar to the P35 Platinum. It has greater potential than its predecessor. The P35 Diamond motherboard can support Intel 1333MHz multi-core processors and use 1066MHz DDR3 memory modules for outstanding performance ().

When overclocked, the P35 Diamond has the same excellent overclocking performance as the P35 Platinum, but with some differences. Thanks to DDR3 memory, users have the opportunity fine tuning some components, such as supply voltage and frequency ratio, which will affect the overclocking results. Finally, we'll take a closer look at the subtleties that you should keep in mind when starting overclocking.

Adviсe:
Overclocking increases the voltage of the main devices, and they generate more heat than usual. Therefore, cooling becomes an important issue during overclocking.

Attention:
OS is a software environment that any computer user comes into contact with every day. The stability of the OS determines the performance of the system. We recommend that users set the default settings during OS installation and do not enable any overclocking or optimization features.

We used an Intel Core 2 Duo E6850 processor with the P35 Diamond motherboard. Memory modules provided by Corsair CM3X1024-1066C7 DDR3-1066 graphics card Nvidia GeForce 8600GTS HDD Western Digital WD740ADFD.

Memory modules Corsair CM3X1024-1066C7 DDR3-1066/7-7-7-21/1024MB/1.5V

DDR3 memory has lower operating voltage, heat generation and higher clock speed, which provides better overclocking performance. When installing memory modules, setting the supply voltage is important.

Standard BIOS setting:

Window view of the program for determining system parameters (CPU-Z 1.40):

The next step is to enter the "Cell Menu" section in the BIOS. Next we set the frequency to 450MHz, frequency multiplier 8, which guarantees stability. According to the P35 chipset specification, as the CPU frequency increases, the memory frequency also changes. Therefore, to achieve stability, we change the FSB/memory frequency ratio to 1:1.

The following image shows the operating parameters we measured (depending on the surrounding conditions)

After completing the settings, you can press "F10" to save the settings and click "OK" to restart the system with the new settings.

Typically overclocking focuses on increasing the processor frequency, which reduces stability but remains a widely used technique. Below is the performance improvement achieved by overclocking.

According to the results, the performance improvement is about 5% and the system is very stable. Of course, users can determine the settings for their environment through step-by-step selection.