ok, well i have had my 1055T overclocked at 3.6ghz with 1.3375 volts for a while and it have been running flawlessly (i folded with it 24/7).
now however i want to get it even higher, im at 3.8ghz right now with 1.4125 v and my NB runs at 2720mhz with 1.16 CPU-NB volts. so when i start running prime im running it without errors for like 15 minutes but then suddenly the PC shuts off, the CPU temp is around 45C when running prime95 so its not overheating.
could this be a PSU issue? i have a nexus 500w PSU with 2x 12V rails, 12v1 is 15 amps and 12v2 is 16 amps.
Your NB voltage may be a little on the low side. Most recommendations I've seen for @2600 with DDR3 are around 1.25v
Not to be rude, but from a quick Google search I would have to say your Nexus may be getting a little long-in-the-tooth. The 5850 your using needs appox. 13 amps. That being said, having 15-16 amps. on the 12v rails might be pushing it to it's limit with the OC you are presently using and it may hinder you from achieving your goal of reaching @3.8
hehe the fun thing is that it is absolutely stable until it shuts down no errors or BSODs during stress testing. do you think that too low CPU-NB voltage may result in instant shutdown? i think it would do a BSOD but not instant shutdown :S
EDIT: forgot to mention that if i get instant shutdown i have to remove the power plug and push the power button a few times or the PC will not start.