The first one cost $400 and the second $200 each one.
My computer has a intel ivy bridge i7 processor and 8gb of ram.
I want to play games and 3d renderings.
What combination is better?
The first one cost $400 and the second $200 each one.
My computer has a intel ivy bridge i7 processor and 8gb of ram.
I want to play games and 3d renderings.
What combination is better?
It is usually better to have one very fast card rather than two half speed cards.
Reasons for using one fast card:
Reason for using two cards:
Having said all that, the 7870 is not half the speed of the 7970. It is about 60% of the speed. Nor will you gain double speed with SL/Crossfire. The speed gain is usually around 80% to 90%, depending on the application. (Read, some games scale better with more cards. Some do it poorly. And as stated some do not do that at all).
For me, the choice would be easy. One card for stability and in this case for near equal performance of the two cards.
Added a card to make comparisons a bit easier.
The 7970 has a PassMark score of 5093; the 7870 has a 3442. As such, the 2x7870 could theoretically exceed the performance of the 7970. However, it wouldn't do so by a wide margin, so I think I'd stick with the stability and upgradeability benefits of the single-card configuration.
But wait! You say you do 3D rendering; in Blender, per chance? If so, you should probably know that the Cycles engine doesn't support AMD GPUs as of yet, and it doesn't look like it's going to for a while. This is the primary reason why I regret buying an AMD card.