PC slowing down, freezing and crashing

Hi guys,

For a week now I've been having an issue with my PC, where after a period of normal usage it slows down, losing responsiveness, starts to freeze and eventually crashes. While this happens, I can still see stuff on the screen, I can move my mouse around but nothing really responds to my input. After a minute or two, the PC just crashes (I've only got 1 BSOD so far, see attached).

I've run memtest86+, no errors. SSD toolbox says the drive is healthy. I've also reinstalled Windows 8 on my boot SSD, but the problem persists. This makes me think it's hardware-related, but I don't really know what to do next.

Any help anyone could offer would be much appreciated.

I'm running the following build as per TSG SysInfo:

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 8 Pro, 64 bit
Processor: Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz, Intel64 Family 6 Model 42 Stepping 7
Processor Count: 8
RAM: 8175 Mb
Graphics Card: AMD Radeon HD 6800 Series, 1024 Mb
Hard Drives: C: Total - 60704 MB, Free - 18340 MB; D: Total - 1012107 MB, Free - 650354 MB; E: Total - 51301 MB, Free - 19711 MB; F: Total - 128798 MB, Free - 18633 MB;
Motherboard: Gigabyte Technology Co., Ltd., PA65-UD3-B3
Antivirus: Windows Defender, Disabled

My list of components:

Crucial M4 64GB 64GB
GeIL Black Dragon GB38GB1333C9DC
Gigabyte GA-PA65-UD3-B3
Intel Core I7 2600K
MSI R6850 Cyclone 1GD5 Power Edition/OC
Samsung SH-S222AB
Akasa AK-ICR-14 USB 3.0 Internal 6-Port Card Reader
Cooler Master Sileo 500 + 500WATT PSU

Thank you!

Attached Thumbnails