Overclocking greatly varies due to what hardware is being used and who is doing the overclocking. Always remember that no two pieces of hardware will perform the same, so our results will differ from what you will might be able to get.
With stock BIOS settings, the Intel Core 2 Quad Q9300 runs with a 333MHz bus speed and has a 7.5 multiplier that are used to reach the final core clock of 2.50GHz. As you can see above, the ASUS P5E3 Deluxe motherboard FSB runs at 334.0MHz, so right out of the box we were running 1MHz higher than stock settings. Let’s start off by overclocking without adjusting any voltages to see what the Q9300 quad-core processor can do out of the box.
The ASUS P5E3 Deluxe motherboard BIOS is very simple to use and to see what the processor could do with default settings we just had to increase the ‘FSB Frequency’ setting from 333MHz to 400MHz. Just by making this one adjustment the board really picks up some speed and you can feel it when using applications.
By leaving all the settings in the BIOS on ‘auto’ we increased the FSB speed to 400MHz and the system was rock solid. By increasing the FSB to 400MHz we could now run the DDR3 memory at 1600MHz versus the previous speed of 1333MHz. It also allowed for the overall clock frequency to increase from 2.5GHz to 3.0GHz. Not bad for leaving everything in the BIOS on ‘Auto’ other than the Front Side Bus Frequency!
With the voltage still set to auto we kept increasing the FSB until the board became unstable. We were able to reach 450MHz FSB before things started to get unstable. By increasing the FSB to 450MHz we could now run the DDR3 memory at 1800MHz, which provides some serious bandwidth with 7-7-7-20 timings.
It was possible to reach a bus speed of 470MHz, but we had to run the processor at 1.3125V in order for the Intel Core 2 Quad Q9300 to be able to reach these speeds. This is just over a 1GHz overclock, which is very nice. The Corsair DOMINATOR 1800MHz memory kit was able to run stable at 1880MHz with 7-7-7-20 timings with 2.1V. This is ~41% higher clock frequency improvement! Overclocking varies from processor to processor and will void your warranty, so no complaints on this nice speed boost.
When it comes to benchmarks, the overclocked Intel Core 2 Quad Q9300 was a monster. The 41% clock frequency improvement improved performance 28% and actually put the Q9300 above the QX9770! The only setup faster was skulltrail at stock settings, but remember that has eight cores!