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 might be able to get.
With stock BIOS settings, the Intel Core 2 Quad Q9400 runs with a 333MHz bus speed and an 8.0x multiplier that is used to reach the final core clock of 2.66GHz. As you can see above, the ASUS P5E3 Deluxe motherboard FSB runs at 334MHz, so right out of the box the FSB is a little higher than one may have expected. Let’s start off by overclocking without adjusting any voltages to see what the Q9550 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 increased the ‘FSB Frequency’ setting from 333MHz to 400MHz and found the board to be 100% stable. By increasing the FSB Frequency up to 450MHz the board was again stable, which is impressive for auto settings.
With a FSB of 450MHz the overall clock frequency was increase from 2.66GHz to 3.60GHz. Not bad for leaving everything in the BIOS on ‘Auto’ other than the Front Side Bus Frequency! Let’s see how far this processor can go!
In our attempt to reach the highest possible frequency we reached a bus speed of 478MHz, but we had to run the processor at 1.400V in order for the Intel Core 2 Quad Q9400 to be able to reach these speeds. This rounds up to being a ~1.2GHz overclock, which very nice. It should be pointed out that several processors have reached a FSB of 478MHz FSB and that this an overclocking wall on this motherboard. With a different motherboard an even higher overclock could be reached with ease.
When it comes to benchmarks, the overclocked Intel Core 2 Quad Q9400 processor was able to complete the benchmark just as fast as the Intel Core i7 940 processor, which is wicked fast. With a different motherboard 4GHz+ should be easily reached and that means it would run even faster!