I previously had this issue: My fps wasn't effected, but my screen was. My screen skipped every 3 seconds without fail.. consistently. I did all of this troubleshooting, and I even tweaked my monitors resolution and refresh rate. Nothing helped it. Where I live, I had HORRIBLE DNS ISSUES so I figured this could be the cause. To fix my graphics problem, I had tried EVERYTHING from flushing dns, adding a manual dns, restarting router, doing an sfc scan, chckdsk, changing all driver settings and in-game settings appropriately. Blah blah blah, the solution was my router. It took a few resets, but it finally cleared up BOTH issues. :\
Double post
It can be the smallest things...
Motherboard: 990FX Sabertooth
Processor: Amd FX-8150 8 core 4.2 ghz
Ram: 16GB 1600 DDR3 Vengeance
Video: GTX 680 SC+
HDD: Western Digital 500GB 7200 RPM 64MB cahe duo core (Black Edition) ----------------------- Soon to add a Hybrid Drive
Power Supply: 1000Watt 80 Gold Modular
Case: Antec 900 (4 fans) -- Soon to add a water cooling unit