Me and my friends are having some problems with C2 after installing 1.9 patch.
It seems like the game in Multiplayer (as I haven't tried in Singleplayer yet) started lagging too much for no reason. Even though my graphics card doesn't support DX11 and that I set Graphics settings on minimum (High), it still lags in fps (it means it's not the internet connection problem). I have an average card - Nvidia 9600 GT. My friend has the same problem and he has ATI HD 4870 card, which is pretty good. And by that, I am sure the problem is not ours.

Any help is appreciated!

Well, yea.. Same thing is happening to me as well.
Game is working for me exactly the same (lagging a lot) on extreme and on high graphics settings after updating the game to 1.9 patch.
I have the same graphics card as your friend, ATI HD 4870 card and 4 GBs of RAM.
The game worked great before this patch, on "Extreme" settings without any fps lag.
What's happening?

The new motion blur and the changed SSAO and SSDO settings are probably what causes it because the new motion blur is more taxing than the previous type.

Can we fix the problem then, and how?

I have the same problem after patch 1.9 lags more Crytek fix fps lag please. Sinds game is out im still not able to play Crysis 2 Multiplayer.

Great Graphics But Great Lags. ( AA is of btw ) I have Sapphire HD6950 2G

Can u please put something so we can play with the patch before 1.9?
Cry - Adam?

Same thing, everything disabled, set only to high, motion blur off. MP got increasingly unplayable as a match progressed. I noticed in Afterburner that my vram was constantly riding at full (sli 460s w/768mb).

Resetting my crisis2.exe profile in nVidia control panel and then turning Anisotropic Filtering OFF brought the vram usage down to 1/2+ to 2/3, where it was before 1.9. Stutter gone, lag gone, dying less.

Also note with this patch, Global illumination is enabled by default. You can disable it by using e_gi = 0 in the console/

1.9 patch kills performance in DX9 for me ass well...

We have to change graphic settings in the game as well as in the nvidia game profiles panel like CH4NCE posted...
Depending on what your hardware is... the GPU actually.

I think this is something that will probably not be solved with a next Crysis2 patch but a gpu driver update.