In game, as long as I don't do anything, it can stay up without any crashes for several hours (I was doing that at first as ways to tests if everything was stable or not). Here is a more detailed description of the symptoms: I start the game, load my save, everything is fine. Since then I switched to Windows 8.1 and now the technical preview of Windows 10, the crashes occurred on all the OS, even on clean installations without any additional software except steam + my current games (The Witcher 3 atm). I was using windows 7 when the first crashes occurred (it was this January, I bought the above configuration as a Christmas gift). My tower is also very well cooled with three noctua 120mm fans (added to the two coming with the case, a fractal design arctic white) and a NH-u12s cpu cooler. I also have two SSDs (my main one, new, for my gaming Windows system, and an older one I'm still using for dual boot on a Linux for my work) and a 3TB hard drive for all the data.

Ram: Crucial Ballistix Sport 16GB Kit (8GBx2) DDR3 1600 MT/s (PC3-12800) GC: GIGABYTE GV-N970IXOC-4GD GeForce GTX 970 4GB 256-B

It crashes, a lot, but only during specific circumstances: when I'm actively using it, especially gaming. Here it is: my system is really unstable. I have a history of building my own PCs so I know a thing or two but it's the first time I'm having so much troubles with a problem that seems to have so many solutions at first. I'm having a lot of issues with my new computer. Only thing that worked (but NOT satisfactory): underclothing -200Mhz memory & core clocks. I tried a lot of solutions, including GPU RMA, re-formatting and changing my OS three times, buying a new PSU and CPU cooler, clearing the CMOS, flashing the BIOS of motherboard and gpu. System crashes (freeze & reboot) when I'm actively playing (not if the game is launched but idle). Here is a TL DR, full post with details bellow: Hello! This is my first post here so first of all: nice to meet you!

Evga precision x crashing gpu