The following is a guide to tweaking your RavenShield and User .ini files to improve game performance legally
These are not hacks assuming you dont break set rules like gamma = 70.0 is illegal via punkbuster
basically if you have at least some technical knowlege you should be able to fine tune RvS to your pc with this guide:
http://warpedsoap.com/media/RvSTweaks.pdf
It covers things like forecing higher frame rates and allowing for all posible resolutions as supported by your moniter
This explains some basic terms like NetSpeed as they apply to the UT engine(which is used in RVS & AAO & UT):
http://forum.americasarmy.com/viewtopic.php?t=25739
As Always MAKE BACKUPS in the case Ravenshield fails to load or you expierence worse gameplay just use the backups.