i can get a great deal on both but the gtx650ti will cost double the gt640.
I can not find enough benchmarks or test videos to choose. I know the specs and yes the 650 ti is much more ....well everything than the gt640; however will the 650ti just
be overkill and i wouldn't be able to tell the diff anyway?
well, i am adding one of these cards to achieve physx support in my amd build. i posted a similar question last week about adding in the 650ti and the two responses were to sell my hd7850 and go all nvidia 650ti's or 660's. but i am on a 150 dollar max budget and want to keep my set up but have physx support.
MSI 970A-G46 MOBO
AMD FX-6100 OC'd to 4.05 ghz
16 Gb Gskill ripjaws 1600
2x500 Gb Seagate HDD
1000 Watt Antec Psu
Antec 900 case with 5 case fans
1680x1050 res monitor
Check the CUDA cores on the 640 vs. the 650. If they are the same the PhysX performance should be very similar (depends on OEM versions vs. retail, Ti vs. non-Ti, etc.). Clock speed may play a small role, but the CUDA core count is most important. It may be that the 640 will do just fine if the CUDA core count matches up with the 650. http://1pcent.com/?p=169
Edit: After reading your post more carefully, it appears you are choosing between the 650 Ti (768 CUDA cores) vs. the 640 (384 CUDA cores). The 650 Ti, as shown in the link above is significantly better, but the question is whether its enough to justify the higher price. I'm guessing the answer is no, but you should also consider the 650 non-Ti for a cheaper alternative.
Yea, the 650Ti is the pinnacle at the moment of a dedicated physx card anything beyond it is wasted. A 650Ti has quite a bit more performance then the 640 and with regards to physx I believe the cuda cores have more of a impact on things and that is the huge difference with regards to physx and the 650Ti versus the 640.
Because of the 2nd number keep in mind that its ever so telling with graphics card the 2nd number in a series of cards. The 640 is a more modern card with new tech, however, the 285 is a workhorse cards the 6,7,8 series cards from nvidia have always been the statement of the entry, to high end gaming with the 5 getting you a little bit into the game.
The way I normally go at it is this. If you have a current gen card and you are playing a brand new game that uses physx typically they will recommend a previous gen card. For example when batman arkham city came out they recommended a 570 paired with a 460 as a dedicated physx card with high physx settings. So you could apply the same logic here. If you had a 600 series card a 500 series card would probably be the recommendation now. However same generation card you could geta way with a 4/5 series gpu but come the next gen cards you may want something like a gtx770+gtx660 or a equivalent AMD card plus hacked driver.