Quadro 2000 v. gtx 570 v. Quadro 4000

Question

Can anyone comment on the MPE performance difference between the Quadro 2000, the gtx 570 and the Quadro 4000?  I'll be using hacked GH2 footage with CBR intra-frame coding, which (I'm told!) can and should be put on AVC Intra time-lines (not AVCHD). 
I'm concerned most with time-line responsiveness and playback performance.  DVD encoding, exporting footage, etc., won't be happening very often, so that's of less concern. 
I'm aware that the gtx 570 is probably the best buy of the three; but that's not the question.  Many thanks.

Answer 1

In any case, performance wise the Quadro 2000 is a waste of money: It costs almost $400, yet it performs equally as slowly as a $100 card. And in Premiere Pro CS5.5, the encoding performance becomes significantly slower with lesser GPUs. Look up posts by Bill Gehrke and you may find a list of GPUs along with their performance charts in the PPBM5 benchmarks. Bill tested a wide range of GPUs from a GTX 580 all the way down to an old 9500 GT. Pay particular attention to the MPEG-2 DVD scores. You will find that even on an overclocked i7-2600K system, the system with a GTX 550 Ti took more than twice as long (146 seconds) as the GTX 580 (60 seconds) or even a GTX 560 Ti 448-core (68 seconds) in that test. The Quadro 2000 would have performed even slower than the GTX 550 Ti in that same test (heck, the GTX 550 Ti itself is slightly slower than a first-generation GTX 260 in this test despite having an equal number of CUDA cores due to the 550 Ti's slightly lower total memory bandwidth). The Quadro 4000 would have performed roughly on a par with Bill's tested GTX 285 (117 seconds) in that same test.
On the other hand, if you're encoding to H.264, then the Quadro 2000 would have been only slightly slower than the GTX 570; you would have had to downgrade further to Quadro 600 (GeForce GT 430) level to see a significant degradation of H.264 encoding performance.
Secondly, the Quadro 2000 has only 1GB of RAM total. With your footage, it is possible that any effects that you apply will eat up more than the amount of memory on the card. If a scene needs 1.5GB of VRAM to render using MPE GPU mode, then the 1GB card will run out of RAM. And when the rendering job runs out of VRAM, that entire frame or scene will default entirely to the MPE software-only mode, which will result in slower performance and may also degrade image quality.
And I strongly recommend avoiding the purchase of off-the-shelf PCs or workstations to begin with: Those systems are way too expensive for such bottom-of-the-barrel performance, and upgrading such a system via the manufacturer would have cost you three to four times more than if you bought those same parts elsewhere. If you can't build an editing workstation yourself (or find it too much of a bother), consider contacting a vendor who specializes in custom-configured editing systems such as ADK.