|A couple of things to know for Core 2 setups....|
- the CPU:RAM frequency ratio should be either 1:1 or 1:2
- the higher the FSB, the better the performance
- try to take advantage of the motherboard's capabilities
Here's your board specs: http://www.asus.com/Motherboards/P5...
Here's the E7500 specs: http://ark.intel.com/products/36503/
The E7500's default clock settings are 11 x 266MHz & it has a max safe voltage of 1.3625v. Your board is capable of at least 1600MHz FSB (400MHz). Unfortunately your RAM is only DDR3-1333 (667MHz) - if it won't overclock to 800MHz (1:2 ratio), you can underclock it to 400Mhz (1:1 ratio) to allow a better CPU overclock. The advantage of the underclocked RAM is that you'd be able to tighten up on the timings.
If it were my system, I would shoot for either 3.6GHz (9 x 400), 3.8GHz (9.5 x 400), or 4.0GHz (10 x 400) with the RAM at 400MHz with tight timings. No need to play with the RAM voltage but you would likely need to increase the CPU voltage to stabilize the overclock. As long as you keep it within the safe voltage range & the temp remains reasonable, it should be OK.
Here's the Q9505 specs: http://ark.intel.com/products/42920...
The Q9505 won't overclock as high as the E7500. It's default clock settings are 8.5 x 333MHz & also has a max safe voltage of 1.3625v. However, the lower multiplier puts it at a disadvantage. Increasing the CPU frequency from 333MHz to 400MHz will only put the clock speed at 3.4GHz therefore it won't perform as well as the OC'd E7500, except possibly on multi-threaded apps that can make full use of the additional cores.
In other words, your upgrade may actually be a downgrade.
message edited by riider