which graphic card is best for solidworks 2011 for rendering and animation
The big issue here, in my opinion, is if you want RealView graphics or not, because you have to go with an approved graphics card to get RealView, i.e. an ATI or NVIDIA "pro" model.
Since you ask for cards for rendering and animation it would be stupid not to get RealView, because it enables you to save high quality screen renders very quickly for a multitude of uses, most notably very fast video rendering compared to PhotoView360 rendering. We are talking 5 minutes for producing a clip versus 5 hours.
I used to work with SolidWorks on a Radon 5850 (without RealView) and it performed beautiful (fast, stable, perfect screen image) but I felt that I missed out on not having RealView, so I "downgraded" to an NVIDEA Quadro 600, which is a puny little expensive toyish-looking card compared to the ATI, BUT it does the job and has RealView graphics and honestly I wouldn't go back to a non-RealView card again. Ever.
Get any of the NVIDIA Quadro series... basically whatever your $$ can afford. You should always check the SW HQ website to make sure that they've tested show that vid card as one that's been 100% approved. Last thing you want is a dud upon arrival.
Yes, Nebule. When you open the model (or change from non-RealView to RealView) some RealView data are calculated by the CPU. This takes only 10-20 seconds for a large model. Thereafter everything is done "on the fly" by the GPU and is almost instantaneous.