Research your Processor
Having never overclocked a PC in my life the first step was to do some research. Just entering overclocking into Google gives plenty of resources for you to read up on the topic. To narrow it down trying entering the name of your processor as well, chances are you will find plenty of people giving reports on how they overclocked your exact processor.
I found several people that had overclocked the QX9650 to around the 4Ghz level without much difficulty. The more serious overclockers have managed 4.5Ghz using just air cooling. While I am not interested in trying to reach such record breaking levels, if there is some free extra processing power available then I might as well grab it.
Overclocking Tools
Getting started means downloading some tools. Start with the excellent CPU-Z utility which gives detailed feedback on your machines setup. Next you need a tool that can be used to stress test the processor and memory to check if your new settings are stable. I used OCCT which was created by a group of French overclockers and is really simple to use. It thrashes all four cores and memory and when it detects a stability problem gives a nice sound effect to alert you.
The bane of all overclockers is the processor temperature, I used SpeedFan to monitor and graph the temp of all four cores. No point in running fast if that expensive silicone is being turned into cheap charcoal.
Baseline
As all good programmers know, measuring performance requires a baseline set of data to use as a point of comparison. Here is the default setup of the hardware via CPU-Z…

To measure the real world performance of the machine I am going to use my build script. There are plenty of synthetic tools to measure the raw performance of memory, processor, graphics and so forth. But as far as I’m concerned I want to see the benefit in real work and not just some theoretical benchmark. Running the build of Krypton game a time slightly over 36 minutes…

Note that I only ran this test just once. To be more accurate I should have run it half a dozen times and taken an average of the different times. But frankly I am not bothered with that level of accuracy and don’t want to spend 3 hours gathering the data.
Updating the BIOS
Doing the actual overclocking is simple. Enter the BIOS at startup and then modify the cpu multiplier. You can see in the CPU-Z picture above that the default multiple of 9 gives a 3GHz speed based on the base 333Mhz speed of the bus. I can increase this in 0.5 increments via te BIOS and so did just that. Adding 0.5 and then running the OCCT stability test for 30 minutes to ensure it was stable and watching SpeedFan to ensure the processor was not cooking.
Repeating this process I managed to get a stable system with a multiple of 10.5 giving a cpu speed of 3.496Ghz with the temp peaking at around 63c. Going above this caused the system to become unstable with regular crashes.
In order to get stable again I increased the voltage to the cpu. Usually this will solve the instability at the cost of running the cpu hotter. Slowly increasing the voltage caused the temp to increase markedly and too much for my liking. Once I was getting 75c I decide to stop as I don’t want to fry a very expensive processor.
Note that I am using the stock Intel cpu fan that comes with the processor. Switching to an aftermarket cooler/fan would probably have reduced the temperature enough to get a higher stable multiple. I did buy a Zalman fan for my machine but it was far to noisey for me to tolerate listening to all day long, so I switched it out for the stock fan before starting the overclocking.
I now changed tack and tried overclocking the bus speed, giving a boost to the FSB and the processor at the same time. This has the added benefit that you can make small increments in the cpu speed rather than having to jump in large increments.
Starting from the default of 333Mhz I upped the value a little at a time until the system become unstable. Then backing up to the last good setting I managed to achieve 340Mhz. This gives a FSB speed of 1360 and ups the processor to 3.570Ghz. You can see the settings here…

This seems to be about the best I can manage. If the cpu is any faster the temperature goes to high for my liking and making the bus faster results in an unstable system. This is someway short of the 4Ghz that others report but the I am using a stock Intel fan for cooling and bog standard DDR2 memory.
Real world performance
But how does this impact actual real world performance? Running our build script we now get just under 31 minutes…

This represents an improvement of 16% which is very close to the actual processor overclocking of 19%. Given the build process includes a fair amount of reading/writing to disk this is very respectable. I then ran the OCCT stability test for 9 hours overnight and it didn’t crash. So I feel confident in leaving these settings alone and running with them all the time. After all, why turn down a free speedup of 500Mhz!
Intel Observations
It seems strange that Intel are releasing processors that seem to be capable of running so much faster. Why would you sell processors rated at 3Ghz when clearly they can run much faster? Obviously they are going to sell them with a safety margin but the difference between the rating and actual maximum speed seems odd.
I don’t remember previous generations from either AMD or Intel having this level of overclocking ability. Are Intel deliberately holding back because they already have a big performance lead over AMD? If AMD start to catch up would Intel suddenly start selling faster rated processors? I wonder.









