I think you could give that GTX 570 a shot at workstation duty. See how well it performs. What applications are running on the workstation?
None now but games, WOW, Starcraft 2 demo. Will get the Starcraft 2 game and others. Software planning to use is 3-D program and a 2-D animation program.
The Gigabyte GV-N570D5 PCI-e power plugs on the top side and not sticking out the back. That's good for being able to fit into tight spaces.
How many fans does that XPS 420 case have?
2, one blowing out the back and one blowing air away from the cpu thru the front of the case.