Just wanted to share something that may help some people. I have been having considerable performance issues with Coverflow on the PC I use for development which is running 2 980's in SLI, custom watercooled, needless to say the performance issues are not spec related. Today I was determined to figure it out, I tweaked advanced video settings, turned off gsync, changed my refresh rate, removed my video drivers and did a clean install, tried a bunch of things. Last thing I tried was turning off SLI and sure enough that was it. I have no idea why SLI would cause that, maybe my other card is defective, maybe its because im running an i7-5820K so the second card is only getting 8 pcie lanes in SLI, no idea. Curious if this resolves issues for anyone else.