How High Can I Stably OC My Q9400 (with stock fan)

[ckaz]

It seems that when overclocking, you need to set out for a certain speed you are aiming for, and then work up from there. What is the highest stable speed when using the stock fan? In the future I will be purchasing a better cooling system but right now that isn't on the budget, so what can I pull off stably using the stock fan. Just to remind, the CPU comes at 2.66Ghz. It is possible I will be purchasing the Arctic Silver 5 thermal paste, but for now lets just go with saying that everything is stock. Any additional component information I can supply, I'm just not sure if its necessary for my two questions, hence me not posting it originally.

 

[festerovic]

It will require a lot of testing to determine the highest speeds.
Read this guide:
http://www.tomshardware.com/forum/240001-29-howto-overclock-quads-duals-guide