Do you mean you tried the stuff from the thread about turning off bullet holes and blood and stuff?
There are a lot of things that you can turn down, I've got a lot of stuff turned down, only one gets warned in some servers. I don't think it makes much difference in my FPS though, any more than the settings suggested
HERE, but I still leave them turned down.
I can show you what I've done, don't know if it will help because if the basic stuff didn't fix your "lag", I don't know if anything will.