I was having serious problems with slowdowns on my system, which is the following:
Athlon 64 FX-57
2Gb system Ram
2 400Gb SATA drives
2 x GeForce 7800GTX (in SLI)
I was esepcially having 10 and less FPS in Vegas.
I've since managed to apply some manual profile settings that made my R6V sessions vastly smoother. These settings may help those of you having performance issues until the next Nvidia driver comes out that has an official profile.
Firstly I suggest anyone with Nvidia cards go and grab the nHancer tool, which you can find HERE.
nHancer makes editing and creating profiles very easy. Once installed, run nHancer.
You should create a profile and make sure that you add the Rainbow Six Vegas executable file called R6Vegas_Game.exe, which is in the Binaries folder of the Rainbow Six Vegas installation directory.
Be sure not to select the Rainbow Six launcher executable as this is irrelevant for the profile.
Click on the SLI tab and then tick the Override box to enable SLI settings. There are lots of setting combinatiuons in hee but all you really need to do is click on the AFR2 button at the bottom right of the nHancer screen. This enables the most common SLI settings that allow SLI to work in many games that use thge Unreal engine.
Once done, simply exit nHancer (there's no Save settings option - all your changes are saved when you exit.
If you feel the need, you can play around with other nHancer settings to see if you can further tweak performance.
This totally transformed my R6V sessions and everything is running smoothly. I'm not sure how to get FPS display so I'm unable to give you all exact figures.
You may want to add this to the stickied tweak thread.
yup AFR2 works best for me as well... you dont need nhancer... the new control panel works fine for adding profiles (old control panel doesnt work well on my vid card)... i didnt get much boost though... only about 20% fps increase.... the biggest boost came from setting shadows to very low... you still get normal shadows just that the swaying tree shadows are low and you dont have a shadow anymore..... but it doubled my fps.... im playing at 1920x1200 i was getting as low as 9 fps in some areas... now in the same place its 19
EDIT: my vid card is geforce 7950gx2 w/ 93.81 drivers