8800GT SLI lagging after changing settings in-game (Crysis)

Sephirangel

Distinguished
Oct 13, 2008
23
0
18,510
Hey guys,
If any of you viewed my previous thread, I was enquiring about whether to buy a GTX260 or just buy another 8800GT to SLI with my current one. In the end I managed to find a cheap new 8800GT which I installed into my system no problem, with pretty good effects! (getting an extra 15-20 FPS in Crysis on "High" settings).
However, if I change the settings say, to 4x Anti-Aliasing, it will lag massively (i tried this while experimenting with the settings seeing how much 'juice' i could get out of the newly SLI'ed cards). I then changed back to 0x aa and resumed play, expecting play to be fluid like it previously was.
However, the frame rate was much lower than the settings previous. I came out of the game and checked the nVidia control panel, and SLI had been turned off for some unknown and bizarre reason! After turning back on, i tried the same thing again, and the same results happened, apart from SLI on the control panel was still on!

Anyone have any idea why settings would be much lower after reverting to and from 4x AA?