Lag :
Using multiple monitors will force the card to work at near max clock full time regardless of load. I use Nvidiainspector to solve this, and it has worked great so far. The only drawback is that you have to add the programs you want to run at full speed manually, but it's worth it for better idle temps. MSI GTX 970 here btw.
For real? A bit disappointing if it is true(and a step backwards).
I jumped to Nvidia in my media center for lower power consumption on Video and multi monitor. If my 650ti can stay at min clock on 2 screen and my 670(680pcb version) can do the same, I am kind of surprised that this happens.
I know some AMD cards would go to a mid level clock with multi monitor, but I thought Nvidia had solved this issue.