You might look at Olaf Cortens OCUS benchmark for pro/e at www.proesite.com. I remember when I last tested video cards about 2 years ago, we couldn't find much difference in performance between the quadro 2000, 4000, and 5000 on Wildfire 4. But, I was told that Creo 2 was able to take advantage of the higher end cards performance where WF4 was not. A computer builder (Gruman Creations) contacted me directly and said he had run the benchmark on creo 2 and had personally seen the high end card perform significantly better on creo 2.
I had the luxury at that time to be able to test the 3 video cards in the same computer. We are currently specifying the Quadro 4000's in our new buys for our HP workstations. I doubt any internal benchmarking has been done on them lately so we may be able to improve our performance on creo 2 with an upgrade but no one has tested it yet.