OCCT GPU 3D Errors, BSODs and artifacts

[georgewesker97]

Last week I started getting BSODs (Uncorrectable hardware error - Stop 0x00000124) after playing some games for a while, at the time I suspected it was my GPU overheating (or CPU, but I monitor my CPU temps regularly and stop playing if they get over 70, so I don't think it was the CPU) which later proved not to be the case.
Lately, it started happening to me that while playing games the game crashes and I start getting artifacts in Steam, YouTube and in a game engine itself though at that point most games won't start, it stops after a restart.
So I decide to run a OCCT GPU test, immediately after the start of the test I got couple of errors and by the end there were 42345 errors, though in the report of everything at the end there are no errors. During the test my GPU hit 112 degrees (105 is Nvidia max ok temp) and I had no BSODs which is why I no longer think it crashes because of a GPU overheat. Is my GPU failing? Anyone have an idea what is going on?

Here are the pictures of the artifacts:
http://gyazo.com/007b8680f879c7b7d2447ab3dcd3bf43
http://gyazo.com/4d81fe438e93cc541d60a25596149a50

Here is a rar file with pictures of results from OCCT:
http://www.mediafire.com/download/n5mlmst5j3f7c2w/13-04.rar

And here are my specs:
MB: Gigabyte GA-880GA-UD3H
CPU: AMD Phenom II x4 965 BE @ 3.8GHz + Cooler Master TX3 Evo
GPU: ASUS GTS 250 1GB
RAM: 4x2GB OCZ 1600MHz
PSU: Cooler Master 600W B-series
HDD: WD 1TB Black

 

[georgewesker97]

Update 1:
BSOD happened again, now ran CHKDSK aswell, no bad sectors.

 

[georgewesker97]

Update 2:
Got a new case with a better airflow in the meantime, wanted to try out BF4 now and 2 times in a row after 10 minutes of playing PC locks up, I hear a repeating stuck sound, BSOD just flashes on the screen and the game restarts (only thing I did after the case change is that I defragd my D drive which is the Data one), atleast now I am completely certain that the cause of BSODs isnt the heat, ran CHKDSK /r now, no bad sectors. I wanted to check the dump files but I only have those from 12 days ago, last 5 BSODs dump files are no where to be found. I'll run Furmark to see if it reports GPU errors as well.