I know 4Ghz is pretty standard these days but I always seem to have a stupid bottleneck of some kind.
I was capping around 3.8 Ghz since I got my current rig a few months ago, I decided it was a mobo limitation and left it at that. Well yesterday I got board and messed around with my QPI, lowered it from 8xx0 to around 2xx0. I was able to raise my fsb to 190 with no issue and was not able to make my computer fail in Prime.
I will push it farther sometime this week.
Processor: i7 920 @ 4.1Ghz (1.26V) Motherboard:Asus P6TD Deluxe Cooling:Thermaltake Frio Memory:12Gb Kingston DDR3 1533Mhz 8-8-60-8 Video Card:AMD HD6970 Hard Disk:2x Seagate LP 2TB + Spinpoint F1 1TB
Edit: haha, I just checked the validation link, I clicked it when I was not under load with Speedstep enabled.
I decided to push farther though, see below.