TF2 performance issues

[Po_Pwide]

Hi guys hope someone can shine some light on a problem my friend is having with Team fortress 2.

His system is as follows:
P4 2.4ghz
Gainward bliss 6800
1 gig ram

when he plays TF2 in sections of any map with no other players his rig runs the game fine. As soon as other players come into play and the action kicks off his rig start to lag real bad, to the point it becomes un-playable.

Does anyone know why this is, and can you offer advise on what he can do to solve the problem.

Cheers Po.

 

[Po_Pwide]

Low setting

He has everything on low already. I have an old spare x800 XT PE and my guess was this card compares well to the 6800 he has, so I was thinking of swapping it with his to test if its the card or something else. I know the x800 card runs it ok on medium coz Ive tested it.

Thing is if he knows whats causing the problem he can replace or upgrade the necessary parts.

Thanks for the feedback so far.