I am running a 560 TI SLI setup with a 850W power supply and a AMD FX-4170 OC CPU. I have been getting 3DMark scores that are lower than I am seeing other people reporting. This is also occurring in Unigine Valley benchmarking program as well.
This has been a problem since I have tried to get the cards working together. They are both 560 TI's but one is a Zoltac and the other is stock. I have verified using the SLI is working using the Nvidia SLI indicator.
Things I have tried:
Updating GPU / CPU drivers.
Toggling "No Snoop" attribute in PCI-E settings within BIOS.
Updated motherboard BIOS.
Turning off power saving mode for GPU.
Installed Win 7 hot fix for AMD BullDozer CPUs (this gave a slight improvement).
OCed stock 560 TI to match clock settings of the Zoltac card.