Nvidia has the Quadro series and ATI has the FireGL series for Workstation graphics. You are going to want to do your homework on these cards to get what you need. The workstation cards are physically 99% like their gaming/desktop counterparts however they are engineered, mostly by drivers, to be optimized for 2d/3d applications. Gaming cards are meant to give you fast action graphics, workstation cards are ment to give you accurate detail and spend more "time" creating such.
The pro (Quadro, FireGL) drivers allow for more control over certain settings in CAD apps, and are geared to accelerate OpenGL pro apps instead of games. The last time I read a review with a gaming card vs. it's pro counterpart playing a game, the pro drivers tended to accelerate games slower than the consumer drivers, and the pro drivers tended to accelerate CAD apps much faster than consumer drivers.
Depends on what you define as CAD. I'm defining it generally as computer aided design - which includes 3d visualization tools like 3dsMAX and MAYA.
In these apps, the GPU makes a huge difference with viewport redraws, even in wireframe only mode with complex meshes. And pro card drivers help a lot in viewport refreshes that include textures and transparency.
When doing a final CPU-based render to an image file, the graphics card doesn't matter, at that point it's all CPU and RAM. The graphics card can absolutely speed up viewport renders, though.
Add to the list of quoted messages Quick edit Edit this message
This is all acracadabra to me, maybe it's some help to you.