I have a 23 inch monitor as my main and I have a 15 inch as a secondary. I have two GTX 570's SLI enabled and have the 23 inch connected through and HDMI and the 15 inch connected with VGA. One card is running the 23 inch through HDMI and the other card is running the 15 inch through VGA. Should both monitors be connected to one card or do I have it set up correctly with each monitor on a seperate card? Also in the NVIDIA control panel under manage 3D settings there is an option "Multi-display/mixed-GPU acceleration" under which there is options for Multiple display performance mode, Single display performance mode and Compatibility performance mode. I don't plan on spanning my desktop across or spanning games across on to both monitors. Right now the 15 inch is just acting as a secondary desktop when surfing and having multiple windows/progs open but not games. Is having a secondary monitor slowing down the SLI or vid card(s)?