I would mainly just like to get some feedback on if anyone knows what my be the cause to my issue before I go about spending money that I dont have at the moment to fix it if I dont need to. Thank you guys for any support you can provide.
Case: Corsair Air 540
Motherboard: Asus M5A97 L.E. R2.0
Processor: FX-8350 (overclocked with a corsair H100i GTX cooler)
Ram: 16gb DDR3
PSU: Rosewill RBR1000MS 1000Watt 80+ Bronze
Gpus: 2x XFX RX 480 8gb (the best buy exclusive version, literally only difference is led fans and a logo but i had a good deal on them because gift certificates)
When playing games the computer will either go to a black screen or freeze entirely and then reboot to the windows login screen. This only occurs when actually entering a game. I can browse windows and load into game menus just fine but when I try to actually play the game it crashes the whole PC by either going to a black screen or freezing then after a minute or so the WIndows logon screen comes up. The games run fine when I remove 1 card and not run crossfire(tested with both cards). It started out with me purchasing a 4k monitor and after setting it up noticing that my framerates were skipping a bit with only one card, so as a result I went out and bought a second since I had wanted a crossfire setup anyways. Got it home, plugged it in, initialized the gpu and enabled crossfire and started testing some game but almost none worked(resulting in the crashes described) and the few that did would stutter and flash black screens every other frame like no tomorrow.
Things I Tried
*Used a new PSU 750watt gorsair 80 gold +
*Tried different HDMI/Display Port cables (long shot but worth a shot)
*Adjusted driver settings and made sure I was on the latest driver version
*Tried new psu cables (swapped out the modular cables)
*Checked power settings
*Checked temperatures(made sure it just wasnt overheating)
My (Maybe Wrong) Theory
I suspect that the issue is my motherboard. My motherboard has 2 PCIE slots 1 running at 4x speed and the other at 16x. From what I had read this wouldnt cause crashes but would bottleneck the cards which is making me skeptical that this might not be the cause, but at this point I think this might be the only thing left unless I am overlooking something. I just want to get some feedback in case anyone else has had this issue and may be able pinpoint the cause.