SLI performance problem

I have 2 8800gts (g92) in SLI in my rig. But ive run a benchmark with SLI enabled and SLI disabled using the GPU benchmark in crysis. And my problem is that i am getting similar FPS either way. With SLI enabled the average was around 28 fps and with it disabled i get around 27 on average. Im no pro on SLI but i would expect a much bigger jump in FPS having the 2 cards over one. Did i miss something? screw something up installing it? I feel like i wasted my money

How large is your display/ what resolution is it set at? SLI really only affects very high resolutions to any noticeable degree

1680x1050. all settings high in crysis.

I would still expect a minimal performance increase. Im getting no performance increase. Ran the benchmarks again and both were 27-28 with or without SLI