Have you tried updating your video card drivers? Maybe that will help speed it up.
As for memory resource hogging, what I do is load into a non-intensive GUI, like IceWM. If you play in GNOME or KDE then that REALLY hogs your system memory. Suffice to say, even playing in IceWM is still laggy for me in some parts of the map. I can only enjoy Counter-Strike in Windows XP.
** I need to amend my statement in that Counter-Strike:Source is unplayable. Counter-strike 1.6 works perfectly with great FPS since it's not graphic intensive.