This problem is been there for more than 2 months now. My PC just reboots withot warning. Happens more often when i am gaming. I checked in event viewer as you can see It just says rebooted without shutting down.
I tried Older Drivers , Different OS Windows 8.1 and Currently Using Windows 10. I even tried by replacing my memory but didn't worked as well. So I Tried to Find where was the problem I Stress Tested my CPU (prime 95, Real Bench) , My ram (Prime 95 , memtest.) Both Remain fine throughout. Then I tried GPU Test Unigine Valley Benchmark 1.0 , Heaven Benchmark 4.0 My PC reboots Just when it starts. I tried 3D Mark but no reboots occurred throughout not even at Fire Strike Ultra witch by the way my system cant handle but it completed the benchmark without reboot.
Operating System: Windows 10 Pro 64-bit (10.0, Build 10240) (10240.th1.150819-1946)
System Manufacturer: Gigabyte Technology Co., Ltd.
System Model: GA-78LMT-USB3
BIOS: Award Modular BIOS v6.00PG
Processor: AMD FX(tm)-6300 Six-Core Processor (6 CPUs), ~3.5GHz
Memory: 8192MB RAM
Available OS Memory: 8174MB RAM
Page File: 2726MB used, 6727MB available
DirectX Version: 12
Card name: AMD Radeon (TM) R9 270 Sapphire Dual-x OC edition
Manufacturer: Advanced Micro Devices, Inc.
Chip type: AMD Radeon Graphics Processor (0x6811)
Dedicated Memory: 2026 MB
Display Driver AMD Catalyst 15.7.1 Win10 64bit