My old PC (AMD X2 388 plus GeForce 7600GS) is dying and I need to get a new one.
I was just about to go and get a Intel Core2Quad 8300 based PC with an ATi Radeon 4830 but I've been seeing a lot of Dell Precision 600 dual Xeon based machines for a bit more. They all tend to have old 128mb Quadro FX1100 / 1400 cards though.
I currently have a bunch of problems on C6 where I can't display texture & lighting properly in the Assemble window regardless of how I set the program up. I keep having to render to see what things actually look like!. Would this be remedied by a better card?
Also, which machine would be suited to faster rendering etc? Can a 5 year old Xeon machine be faster than a modern one?

How important is it to have a high end graphics card, can someone recommend a widely recognised  'good one'?

I also use CS3 products a lot.

Can anyone please help?