Hello everyone..
 
I recently added a 4th GTX 580 3gb to help aid with my surround set up of 8020 x 1600. For some weird reason, ALL of my games are locked at 48fps maximum regardless of the in-game settings. Whether or not Vsync is ON or OFF, I'm capped at 48 fps .  Switched drivers, messed with NVP, no luck.When I revert back to three way SLI, my FPS goes back to normal of 60 and above. I use FRAPS and or the Afterburner FPS utility.  Games I tested are the ff: Batman Arkham City, BF3, BFBC2, Dirt 2, Dirt 3,AvP, RAGE, Medal of Honor, HAWX2, Crysis, Crysis 2., Mafia 2 and so forth. Has anyone experienced this kind of  issue? All drivers are updated, (301.42) BIOSes are also updated to the latest version. Any help or work around would be highly appreciated!!   My PC build are as follows:
 
Asus Rampage 4 Extreme
Intel Core i7 3930 OC'd to 5.1ghz
EVGA GTX 580 Hydrocopper 2, 3gb version in 4 way SLI
Mushkin Redline Series 2133mhz x 16gb DDR3 SDRAM
Silverstone 1500watt PSU
Crucial C300 256gb SSD x 2 in RAID 0
Maingear Shift chassis, (modified Silverstone)
180mm all in one CPU cooler (Epic 180 CPU cooler)
Koolance ERM- 3K3UC all in one external liquid cooler for the GPUs
Bitspower fittings for the GPU  water loop
Samsung 305t x 3 in NVIDIA surround (8020 x 1600)
Wadia 151 PowerDAC mini powering 2 Bowers & Wilkins CM1s (stereo 2.0) USB sound
Windows 7 Home Premium 64bit OS

4-way SLI does not scale as well as tri-SLI in many instances. It's why I dropped back to Tri-SLI on my setup a long time ago.

While I agree with Brad, there is certainly something weird if ALL of your games are capped at 48 FPS.  The 680's seems to scale better (actually all 6XX series) with Quad SLI.  This sounds like a driver issue to me.  Quad SLI will scale  differently in different games.  Some games will be able to use it, some will not, but you shouldn't be getting the same frames in ALL games.