hi, i am new to q4. i have been playing it for a while now, and i constantly experiencing huge lag in some scenes... my setting is pretty much like in Doom 3, and in Doom3 the game ran smoothly, so i was very impressed with what idtech 4 can do to the experience. Nice graphic, but less system drained. but then i am playing Q4, which is awesome and fast pace by the way, i experience huge lag, i have the latest patched installed, i have my video mode (as in my Doom3 setting as well) to Ultra, my screen resolution to 1028x720( as in my Doom3 setting as well), anti aliazing is 4x (as in my Doom3 setting as well), and choose muticore processor (not present in Doom3), also like in Doom 3 i have the vertical sync on.

My spec are as follow:
Core 2 duo 2.20GHz
2G ram
Nvidia GeForce 8600M GS

any help would be appreciated!!
thank you
keith