get gpuz it will tell you what speed your sli is running at idealy you want to see pcie 2.0 x16@x16 on both...
i have issues with 3dmark 11 personally i hate it on a 2600k system with sli'ed 580gtx's its scoring just over yours at stock... if i run heaven or metro benchs it absultly flys...
I'm not sure if my motherboard supports x16 (evga x578) And if it did. How would I configure to run at x16? Do I do that through BIOS?
And I don't have the SLI fix installed.