I currently use a custom built rig operating Windows 8.1, and 8 core processor, 16 gigs of ram, and a AMD 6670 graphics card (not the best I know but I'll talk about this in the future)
I currently do not have my PC specs with me being I'm on a break at work as I am writing this post up.
Now for the issues
Desktop will randomly freeze and become unresponsive
Desktop will randomly turn off. No shut down, no error, no bluescreen. The PC simply turns off. After this happens I will have to hit the switch on the back to turn the PC back on. However there is never a "incorrect shut down" or "hardware failure" message that appears.
I have done a check of the bios files there are some errors (I think associated with the abrupt shut downs)
I recently lost a power supply (RIP) and due to this fact I had to get a new one. The new supply is the same wattage (600W). As it was being replaced the Tech and I were talking about a game that we both play and how our computers were handling it. It came to our attention that my PCs graphics cards were not crossfire compatible as the manufacturer had told me. I took out the primary card and gave it to a friend. I kept the secondary card and use it now.
..then the above symptoms started.
I suspect the secondary graphics card (due to the fact there was no pull on it in the system until now) Because this problem will happen during regular use, but is MUCH more frequent when using 3D applications for gaming. Infact if I leave the PC on idle for a long period of time it will not turn off but will freeze instead (both happen during use however)
steps I've taken.
memory checks (all clear)
reseating the graphics card to ensure a good fit
opening side panel to allow more airflow, later adding a fan to blow air into the PC.
any suggestions on how I might isolate this issue?