Graphic Queston

If you have a free PCIe 16x slot open, shouldn't be any problems fitting it in. Your only concern should be, the PSU, does it supply enough wattage for a GTX280.
 
We bought a 600 Watt power supply and installed after the first one went. Now we are trying to install the video card. Its is quite large but we got the room. This is going to be our CAD computer for a small company I work at.

Axeon:Which IBM ThinkCentre do you have?

THINKCENTRE E8400 3.0G 2GB 160GB DVDRW XPP
 
If you still don't have the performance you're looking for after the installation, you might want to think about upgrading the RAM.