Thanks for the tips guys, i'll try bumping the dram bus voltage up - the ram has run at 1500mhz with it's current timings and voltage, so i'm not sure if it's a problem with the cpu hitting a limit or if i'm not feeding enough voltage into the imc.
As for my temps i'm pretty sure it's because my triple rad is pure sh*t - the pump, res, block and piping is all stuff i've bought individually but the rad came with the case :shadedshu (i've not found a triple rad that fits in the available space in the door to replace it yet) as i get a serious heat build-up if i leave the thing to run for a long time.
She idles at 37-40degrees, after 2 or 3 mins of prime 95 she's hitting 75-78degrees on cores1-3, 69 degrees on core 4 (my core 4 is always very cool compared to the others). If i leave it to run for hours though the temps slowly build up as the rad doesn't cool the coolant enough and so it all builds up)...
It's not my thermal paste either afaik as i'm using AS5 and this is my 3rd application of it since i built the rig (i clean it off properly between applications), used the drawing a line of as5, the smearing a thin film and the pea-sized blob methods and found the pea-sized blob method she's using now to be the most effective (2-3 degrees cooler than previous methods).
#edit#
If i can't get the thing to clock faster with a couple of tweaks now i'll have to leave it until the end of the week as i should be revising for my 4th year exams which i have all week starting tomorrow
I'll put up a new thread for that when the time comes as i'm sure i can push this chip a lot further.
