New GPU, now pc restart's randomly

devilslayersbane

Prominent
May 6, 2017
3
0
510
I recently upgrade my GPU from an EVGA GTX 970 to an XFX RX 580 Black edition and now in ArmA 3 my computer randomly shuts off. I have the latest drivers, BIOS, etc. The microsoft event log really seems unhelpful with the exception of telling me what time my computer shut off at. I'm pretty much at a loss here.

Arma 3 seems to be the only game in which this happens and it is a very CPU intensive game. I have my CPU oc'd at 4.1 GHz and I haven't tried toning that down. However, I felt like it was a safe bet since my computer ran just fine when I only had it oc'd to 4.0 GHz with my 970.
However, I had only been playing about an hour when I got the random restart this past time while I played 4 hours last night with no issues.

Specs:
ASUS Sabertooth X79
Intel i-7 3930K @ 4.1 GHz
16 GB 1866MHz PNY Anarchy RAM
XFX RX 580 Black Edition
240 GB PNY Optima SSD
1TB WD Caviar Blue HDD
1TB Seagate HDD
CPU Cooler: Thermaltake Frio
Other Fans: 2x 200mm fans, 1x 120mm rear exhaust fan
 

devilslayersbane

Prominent
May 6, 2017
3
0
510
Update:
So I've figured out at least a portion of the issue. I had a USB HDD that was actually preventing my Keyboard from turning on last night after another reboot (yet again in arma 3). Somehow, it was also preventing the motherboard from properly loading my boot drive. I cannot find the manufacturer on my Power supply but I know that it is 700Watts. Any suggestions?