I've successfully overclocked my Q9550 to 4GHz (471*8.5), I've attempted to get it to 500*8 and 533*7.5, but have been unsuccessful (I've tried increasing MCH, CPU vCore).

So my question is regarding RAM, I've currently got OCZ PC2-8500C5, but due to the Clock, it's currently underclocked to 471MHz as opposed to 533, is this going to make a dramatical difference to general performance and Gaming?

Secondly, due to the underclock would it be beneficial to decrease the timings to, for example, 4-4-4-12-1T, as opposed to the 5-5-5-18 default timings, even though the BIOS sets it to 5-5-5-15?

Even any tips on getting it to 533*7.5 would be appreciated, but I don't really want to increase the CPU temp, would increasing the FSB only increase the NB Temp, or would it affect the CPU Temp also?

Many thanks.