Concerned system at the end of this post.

I'm experienceing infrequent "black screens" locking up the computer forcing a hard reset and usually, 3 - 7 reboot attempts (the unsuccessful ones halting when trying to load Windows, as far as I can tell due to some sort of graphics-driver loop. More often than not I get around this by booting in to safe mode hence flushing loaded drivers and then rebooting).

The Windows log (event manager/reliability monitor) is of little or no help other than complaining about "unexpected shutdowns" (which technically is relevant but, from my standpoint, not very helpful information). I've tried to reproduce the error using a number of stress testing- and benchmarking tools (Furmark, MSI Kombustor, Valley Benchmark, Superposition Benchmark and 3DMark). I managed to recreate a black screen once(!) using 3DMark's stress test (Timespy), but after a reboot the very same test completed without error. Hence I fail to find any consistency in this behaviour which makes it very hard to exercise any meaningful trouble shooting. (prior to these tests, as a general check up before finally migrating to the system, it was stress tested with Prime95 (blended, 72 hours) and IntelBurntest (50 "rounds"), both tests completed with no errors reported).

Other things I've tried: All available drivers for the graphics card (with and without bundled software), I've even updated the drivers for the integrated gpu (HD 4600) which, I might add, is disabled in BIOS when using the discrete card. Also, I've excluded the striped Samsung-disks below as a potential cause by disabling them and running e.g. games from the SSD, which eventually caused a black screen.

The integrated GPU doesn't seem affected.

Finally: The "black screens" have a tendency to occur when more (or less) graphics intensive applications such as games are running, although on one or two occasions even the desktop have gone black on me. The computer can run even demanding games such as DCS for hours without a hickup, only to produce a black screen when running even a moderately demanding application. Once this has happened they are also repeated within shorter and shorter time intervals.

This could of course be a hardware failure, and I would like to narrow down any theories in that respect to the motherboard and the CPU (and/or the lack of said components compatibility with the rest of the system). My reasoning is based on the fact that I've previously been using the rest of the compononents in another system for a number of years without any issues. The cooling is also adequate (idle/max-load ranges between 30 - 55 Celsius (CPU) and 45 - 65 Celsius (discrete GPU)).

As you probably understand, I'm at my wits' end, so any input would be welcome.


Motherboard: B85M-DS3H
BIOS: F3 (latest available)
CPU: i5-4460
RAM (DDR3): Crucial Tactical (4 x 4GB = 16GB@1600MHz)
PSU: Corsair HX850 (850w who would have guessed...)
Storage: Intel SSD 120GB (OS), Samsung HD501LJ and Samsung HD502HJ 1TB -(striped).