random black lines and pixelated boxes appearing during games

[Vanilla Phoenix]

I've Been having strange screen glitches while playing games lately. Not sure if it's my video card or monitor. They look similar to this...
http://s1.postimage.org/pjdr1xmov/iw5mp_2013_01_06_11_44_48_60.png
It will flash lines just like those and other graphical things to that. Any ideas? Drivers and all should be up to date. It also only happens with games like assassins creed, shadow of mordor, and occasionally league of legends or skyrim.


Intel Core i7 4770k 3.5ghz
Motherboard: Gigabyte Z87x HD3
Video: AMD Radeon R9 270x 2gb gddr5

 

[dominirican3351]

IS your graphics card over clocked and what temps is it running at. Could be gpu artifacts

 

[ConcurrentFlame]

Assuming you recorded those photos with PC software and not external hardware, I should be a problem with your GPU overclocking. Alot of GPUs do things such as begin to pix elate the screen and such when they are overclocked and now a days only in use to save power. My 680 does this when I have it set too high but because it's older it begins to crash to whole display driver unless I cahnge it near/ slightly above stock speed.