System spec:

core 17 @ 3.07GHz
GTX 570 1.3GB (most recent drivers as of 26th March 2011- 266.58)
8GB RAM
Win7 64bit

The single player is completely unplayable- if I had to guess I'd say it was 10-15fps. The game defaulted to extreme but I scaled it back to very high. I also used the graphics program someone created here to turn off all fancy options (motion blur, HDR etc). It doesn't feel like true "graphics lag", it's almost as if vsync has been enabled and set to 15fps.

The MP demo ran well- easily over 60fps at the highest graphics level.

I can't try the retail MP as account login is bugged for this account, and it refuses to accept e-mail addresses for new accounts (I even created an e-mail account today for it, but Crysis 2 still says "e-mail account in use").

Before launching Crysis 2 for the first time I updated to the latest nVidia drivers. Thinking this could be the reason for low fps I ran Crysis Warhead but that runs fine.

Help!

Edit

Okay, used my demo account to try the MP but I get "serial code in use" error. Crytek sort your game out- this is ridiculous.

Finally got into an MP after getting past the serial code in use bug and servers not loading.

MP totally unplayable too. 10-15fps.

Crysis 2 was the main reason for updating to these specs. Very disappointing.

Edit

Rolled back to the nVidia drivers I used for the MP demo- still no better. Used FRAPS: I don't get above 25fps.