I had a similar problem with my system. I was connecting my monitor using a vga cable with a vga to dvi adapter. What solved it for me was switching to a hdmi cable. Since vga is analog, there was some distortion taking place.
You might try using an hdmi or a dvi cable if you are using a vga cable.
Best of luck.
I just built this new rig, and I'm noticing that when I'm playing games, I can notice some faint horizontal lines that distort the colors a bit, either making it lighter or darker. It's almost impossible to notice in light environments, but it's very obvious in dark ones. They jump around and remind me of scan lines on a TV, but very faint. They're probably only a couple of pixels thick each and are mostly around the middle of the screen. They don't appear in screenshots and don't appear outside of games.
I don't know how else I could describe them, english isn't my first language and I've never seen such a thing before. But I am concerned about it and would like to make them go away, or see if anyone knows what it could be.
Here's my specs:
MB: Asus P8z68-v Pro/gen3 Lga 1155
Processor: Intel i7 2700K 3.5GHz
Memory: 2x 8GB Corsair Vengeance DDR3 1600MHz
GFX Card: EVGA Nvidia GeForce GTX 670 2GB DDR5
Power supply: Corsair Enthusiast TX850 V2 850W
Both the card and the processor stay at around 30°C when idle, processor goes to 40°C and card to 70°C when running Battlefield 3 on Ultra.
Any help would be greatly appreciated.