Running SLI/Crossfire, your 2nd card is not being used with DX11

MrChoke

I am 100% sure that the 40 FPS drop when I run with DX11 is because the 2nd viedo card is not used. The SLI/Crossfire profile for NS2 has been out for a very long time but it must not apply to DX11. The experiment for me is simple:

1) Run DX11 and SLI active:
55 FPS, with drops to 30

2) Run DX9 and SLI active:
95 FPS

3) Run DX11 and SLI not-active
55 FPS, with drops to 30

4) Run DX9 and SLI not-active
55 FPS, with drops to 30

If you are having this horrible FPS drop and run 2 video cards, I'd do this test. I am not using DX11 until this is addressed.
BTW, I was having bad input lag as well but for me it was because of the dropping FPS. If you FPS drops from 50 down to 30 or so, it will result in the feeling of input lag.

Sycho

That would explain it. I could always run Ns2 at max with crossfire HD 6850's, now I'm getting absolutely screwed with stuttering and fps drops in B254.

I second your assertion.