Originally Posted by evilferret
nvidia gets a bit whacky with the power saving stuff for me when running multi monitor.
Another option if worried about multi monitor is just get whatever GTX you want and get a cheap budget/power efficient card to run your 2nd monitors to keep load off your main.
(The [...] are where I snipped stuff out of your posts.)
The NVIDIA multi-monitor power saving whackiness comes into play only when you are using multiple monitors that do not have identical resolutions. If you are using two monitors at different resolutions on one NVIDIA card, the drivers disable the power savings P8 and P12 modes (video playback and 2d power saving modes) and remain in P0 mode (high power 3d mode) all of the time.
The reason for this is that with two monitors at unequal resolutions when the drivers switch between power states, the second monitor (and sometimes the main monitor) will go black and flicker briefly for one or two frames. The customers complained about this and NVIDIA decided that disabling power saving mode and keeping customers happy with no flickering was better than even giving the customer the option to "enable power savings, but note that this may cause flicker in multi-monitor environments in some cases."
The solution to this is to download NVIDIA Inspector and enable Multi-Monitor power saving mode at windows login and live with the flicker.
The other solution to this is to make sure that you buy two monitors with identical resolution (they can be different diagonal measurements, as long as both have the same native resolution).
The final solution is the second one that you suggested; get an inexpensive second card simply to run the second monitor and not bridge the cards in SLI.