On 19 inch screens I think "Warhead" will run at its glory with HD4850. But for Crysis I dont remember any single card having good scores against him.
Crysis is the game made to be played in 2012 or even later at higher settings.
My sys:-
AMD Athlon 64 X2 3600+
2GB DDR2 667Mhz [Dual-Channel]
XFX Geforce 7600GT 256MB DDR3 XXX Edition [590,1600]
this thing runs Crysis @ 25fps @ 800x600 @ high-settings @ DX9 in WinXP Pro
what performance can i expect from Crysis:Warhead as well as Far Cry 2 from this machine?
at 800x600 if you reduce the settings just a bit. I think the fps will rise to 40s. Its better to reduce the settings and increase the screen resolution to 1024 X 768. it will give you far better results.
Upgrade is the only word coming to my mind. i tried playing crysis demo without the graphics card on my machine with integrated ati x200 graphics. I played the demo it was ........... playable(I can say as i played) with regular freezings at the time of explosions and heavy firing.
Actually crisis is not the game meant for playing. Its meant to be placed in museum with a tag that this game was played by only few living beings on this planet and due to this reason this game extinguished from our planet..