CPU overclocking

New and improved overclocking tutorial. While these settings will not be 100% the same on other systems, these are just to give users new to overclocking an idea of how to overclock and how the many settings work together. (Updated this tutorial to include more settings that are more relevant to newer systems)

So to get started, here are my system specs.

Motherboard: Asus A8V socket 939

Memory: 2GB (2x 1GB) G.Skill memory

CPU: AMD Opteron 170 dual core (Stock speed: 2.0GHz)

(The rest of the specs are not important as they will not effect this overclock)

Since I already know the systems max overclock, I will be going directly to the max overclock but in the case of any system in which you are overclocking for the first time, you will increase the clock speed 5-10 MHz at a time and if it becomes unstable, you will increase the voltage little by little (while avoiding a unsafe voltages)

Overclocking instructions starts here.

Step 1: Restart your pc and enter your bios setup (in my case, it is the delete key)

Step 2: In the bios setup screen, head to the advanced section and then System frequency/voltage control

Step 3: Using the manual overclocking settings, I will use these settings.

Explanation of each of the settings:

CPU FSB Frequency [290 MHz]: the stock setting is 200 MHz, since the multipliers of almost all modern CPU’s are locked so you can’t increase them past their default but you can decrease them. So to increase the clock speed, we increase the FSB.

CPU Speed/Voltage Setting [Manual]: Simple enough, we set it to manual because we want to have control over the multiplier and voltage.

CPU Multiplier: This along with the FSB determines the clock speed of the CPU 290MHz X 9.5 = 2755MHz (simply times the FSB by the multiplier)

CPU Voltage [1.5V]: This is the voltage headed to the CPU, as you overclock, when the CPU hits a certain clock speed, it will become unstable (Use prime 95 to test your CPU stability), if it becomes unstable, increase the voltage by a small amount and test again until it becomes stable or reach your safe limit which is different for each cpu

(my stock voltage is 1.35V and to hit 2755MHz I had to use 1.5V, I wouldn’t feel safe going any higher)

AGP/PCI Frequency [75.4/37.7]: When you increase the FSB the AGP and PCI clock also goes up, the problem is that after a few MHz, they become unstable so you need to lock their frequency so I picked a slightly overclocked frequency and locked it at those speeds so it doesn’t become unstable

DDR Voltage [2.7V]: My stock voltage was 2.6V as you increase the FSB and CPU speed, the memory clock speed will also go up and you will need to increase its voltage little by little to keep it stable as you overclock until you reach your safe limit

AGP voltage [1.6V]: It is 1.5V by default for my system; I had to use 1.6V since I have a crappy agp version of the radeon 3850 (I regret buying it, crappy opengl drivers, and unstable direct 3D drivers)

V-Link Voltage [2.5V]: no need to mess with it, has no effect on stability and increasing it can actually reduce system stability

Step 4: Since my memory sticks could only handle a 60MHz overclock (DDR400 overclocked to DDR460), I have to change the memory divider so the memory will use a different clock speed ratio so it doesn’t limit the max overclock from my CPU. So to do this, I changed the rated memory speed from DDR400, to DDR333. This changed the ratio enough to allow for more CPU overclocking headroom before the memory hits it’s max clock speed. (at stock speeds, changing the memory divider option from DDR400, to DDR333, will significantly lower the clock speed of your memory, so overclocking of the CPU and FSB will be needed to bring them back up to normal) (PS ignore the memory timings, Since I reached a good overclock on my CPU and my memory still had some headroom left, I lowered the memory timings slightly to get a little more memory performance, while in some cases you can increase the timings to get a higher clock speed out of your memory, it doesn't help in many cases because depending on the memory it may only allow a few more MHz increase but due to the increased timings, you will actually loose system performance)

Step 5: Save changes and boot into windows, and test for stability and also monitor your cpu temperatures to make sure there not running too hot, you generally want to stay under 70C. (each time you make a small change to the settings, save changes and test for stability by running prime 95 on all cpu cores for an hour and when you reach your seemingly max overclock, run prime 95 over night or to be 100% sure, run it for 24 hours (you can still use the pc while prime 95 is running but it is best to leave it alone for 24 hours)

Here are my final results:

The memory went from 200MHz stock (DDR400), to 229.6MHz (basically DDR460)

Other helpful info:

Overclocking takes a while, but you can speed up the process by searching google for reviews and benchmarks on the hardware you plan on overclocking, then in most cases, you can jump right to 60-70% of their overclock and test for system stability and if it is stable, you can just follow normal overclocking steps like the kind I listed until you reach your systems max stable overclock.

If you are reaching high temperatures before you reach your max overclock, you may want to consider getting a better heatsink, a high end heatsink is a good investment because they can generally support multiple cpu models and cpu socket types so you can use them on future cpu's and PC's that you may build.

Be sure to test for stability using prime 95, here is the download link http://majorgeeks.com/Prime95_d4363.html

While this overclock was done on an AMD system, the same basic rules and steps I went through will also apply to intel systems.