PC Restart During Gameplay (SC 2 LOTV, COH 2)

[pss200835]

Dear Masters,

My PC Restart during gameplay (after several minutes, sometimes instantly) at SC 2 (VERY HIGH) CPU and GPU temp are fine, CPU at 50 degC, GPU at 58 degC.

My specs are,

INTEL i5 4590 3.3 ghz cooled by schyte ninja heat sink
GIGABYTE H97M-D3H
Sapphire R9 270X dual-x with latest ATI drivers
VGEN 3x 4 GB DDR3 1600 mhz RAM
CORSAIR VS550 power supply
WD 2x 1TB sata 3 7500 rpm internal HDD
Micro ATX full aluminium casing with 2 x 8 cm fan (exhaust only)
Windows 7 Ultimate

First I thought it is about the RAM,
so I try to use only one RAM at a time, run application that consume most of the RAM, I try to all my RAM, but no issue, run memory diagnostic it is fine.

Second I try the GPU and CPU by using 3D Mark11 Extreme Benchmark Test, no issue, PC is not restarting while record says, GPU load reach 100% CPU load reach nearly 80%.Then my conclusion is it is not GPU/CPU load/overheat nor Power Supply problem, since 3D mark 11 consume more power than gaming.

Any ideas? I never got this problem one month ago.

 

[Tradesman1]

Do you have the latest BIOS and mobo drivers? Could also roll back the GPU driver and see if issues persist, might be the new driver

 

[samucaninja]

Try this, adapting the video card settings from this link to your video card:
http://www.tomshardware.com/forum/id-3015049/desktop-restarting-monitor-standby-mode-game.html