Okay, me and a couple friends at work have been bashing away at this problem for about 2 days now. We built an APU-based machine for a friend, then decided that the best way to improve its actually quite meager performance was to add a dedicated GPU anyway (Dedicated GPU was not much more than faster RAM, and we were re-using 1333MHz stuff, crap for APUs).
Anyway, we installed windows and it seemed fine. He takes it home, suddenly loads of bluescreens when it's idle.
For some reason my friend decided to install a cracked version of win7x64 Ultimate on it. I thought this was the reason, so I put a fresh install of Win7x64 pro (genuine) on it today. Grabbed all the latest drivers from the mobo manufacturer's website (Gigabyte) and copied data back onto it.
It sat on the bench in the office for about 3 hours, backing up, reinstalling windows, installing drivers and restoring files to it. didn't BSOD once. However, now he's got it home again, it's doing it again
It's still a way out of date early SP1 install, I'm thinking after the multitide of WUPDates it needs it will be alright - however I'm not certain enough to bet on that. The disk I used was a Dell OEM Win7 pro disk, pre-loaded to service pack 1.
We're seeing bugchecks relating to Driver IRQLs, paging faults and such. I'm thinking it could be faulty memory, or perhaps BIOS needs updating?
Some error codes we've seen: 0x0000001e, 0x00000050, 0x0000003b
In the past I've only ever seen the 0x50 bugcheck when memory was at fault, however 2 hours of memtest86 threw up no errors.
It only seems to bugcheck when it's idle. It'll sit there running Prime95 FPU/Blend tests or Valley/Heaven benchmark for hours and be fine. As soon as you let it idle for a bit, it bugchecks.
CPU: AMD A10-7870k (Black edition) @ 3.9GHz (Boost 4.1GHz) (Stock clocks, didn't overclock it!) - cooled with a CM AIO cooler
Mobo: Gigabyte F2A88XN-WIFI
GPU: Gigabyte R7 260 (OC Edition) - Didn't overclock this either!
RAM: Corsair XMS3 DDR3-1333 (Running at stock clocks in BIOS on auto-DRAM voltage)
HDD: Seagate SHDD 1TB
PSU: Corsair 550w semi-mod (CS series I think?)
Shout suggestions at me, I know I keep saying 'Friend' in reference to the gent who's PC it is, reality is he's also kinda my boss!