You may want to look at a workstation card for those apps.
Something like a Quadro (Nvidia) or FireGL/FirePro (ATI).
Expensive cards but they're specifically made for CAD apps and while not any gamer video card, they do what they're designed to do much better than the GeForce/Radeon equivalents. I'm no expert and have little to no experience with CAD programs and 3D modeling...I'm sure someone else can back me up on this, or explain in better detail?
The GeForce GT 120 is a fairly weak card by today's standards though. By doing a quick search, you'll find it's a rebranded GeForce 9500 GT...