Weird graphic Artifact

am using Geforce nivdia GTX 680

and been getting these weird artifact (colored in blue and red in pics) everyone now and then

and sometimes whole screen goes yellow
http://i39.tinypic.com/282izr7.png

http://i40.tinypic.com/ajo40p.png

Is your GFX card overclocked?

Quote:

---

Originally Posted by Durakael

Is your GFX card overclocked?

---

nope it is not