Other: While likely not the issue you should do this for now:
1) apply any BIOS firmware update to your motherboard 2) set CPU and RAM to stock speeds 3) run MEMTEST (or type "memory" into the Start Menu and use the memory diagnostic tool)
*FYI: apparently some games run better with one GTX670 used for the main game and one dedicated to PhysX rather than both in SLI. It would vary by the game. I suspect Borderlands 2 would run best this way rather than 2xSLI.
Also, due to micro-stutter (which is not your red-black issue) if a game will run at 60FPS on a single card do so. No need to remove the second card physically.
There are MANY games that hit 60FPS with a single GTX670.
SUMMARY: - single GTX670 mode if games hit 60FPS (max quality or close) - single GTX670 + dedicacted PhysX 670 if a PhysX game runs better that way - 2xGTX670 SLI for very demanding games that run better that way (microstutter but higher frame rates) - again, it's pointless to 2xSLI if a single card hits 60FPS as you introduced micro-stutter but gain no benefit as your monitor 60Hz refresh (60FPS) is already maxed.
That's NOT what micro-stutter is anyway. Micro-stutter is when frames are appearing at uneven times.
Advice: 1) Try Card#1 in your top PCI_E slot (recommended in your manual) 2) Try Card#2 in the same slot 3) repeat for the second PCI_E slot (that your manual recommends for the second card in SLI)
The above is to confirm both the card and the slots when one card is used by itself. Your motherboard will recommend specific slots to be used for 2xSLI so use those.
If the problem doesn't appear with single cards alone, then it's likely your PSU, Motherboard, or software issue.
One step at a time.
Thanks for the list of things to run through. Been working on my new rig all day, and I've got class in the morning so I'm going to have to wait before I attempt to try any of that. I'll update with results tomorrow evening.
Best answer selected by mune87.
Switching the cards worked! To be specific, I switched the cards between my two PCI slots and moved the SLI bridge over to the next slot over. Thanks for the solution!