I am currently running a GTX 570 and am considering to change the card.
With the new Maxwell chips the watt consumption of the NVIDIA cards crashed down a lot
which is nice.
I was considering even two 750 Ti because they run just with the PCI bus power.
However I am not very up to date of which card really would work well for the MacPro 2008.
Well, the 570 and 750ti are pretty similar in terms of performace, but the 750 has more VRAM, much needed for cycles. For an upgrade i would consider something more powerful, as you wouldn’t get much speedup with the 750
Considering the watt usage of the 750Ti I was considering adding actually two. So even when each unite has less cuda power than my 570 two 750 Ti would!
Hi,
Right now one GTX970 is faster than two GTX750ti (due to slowdown in render times since 2.72 for the 750ti) but prices are very close (around 300-350$).
The 970 will have a lower consumption than your 570 and will need 2x 6pin connectors as well so it should be ok.
Another thing is that the 970 comes with 4GB VRAM vs. 2GB for 750Ti.
If you consider going multi-GPU and are ok with 2GB VRAM you could go for 3x 750Ti, which beats the GTX980, but it depends on you.