I just bought a Powercolor AMD 7870 2Gb Tahiti le for gaming, (will be in my primary Pci-e 16x slot)
but i would also like to buy a workstation Firepro card when i want to do some light / medium modeling, simulations etc...
(i would put this can on my second pci-e 8x slot)
I'm looking to buy a used Firepro card, i found 2:
I can't any comparaisons for those 2 card, i'm not sure which perform the better,
all i know is that the V8700 is more a hi-end card but older generation, the V5800 is newer but mid-range.
Based on those price which has the best $ / performance.
last questions: Is the powercolor 7870 will perform better in 3d softwares than those 2 firepro card even if the card is a "gaming" card?
For the work you describe, just stick with the HD7870 and don't worry about trying to get a FirePro to work properly along side it. Honestly, I don't think you'll see any benefit running both in one rig.
If you do decide to get one of the FirePros, the V8700 is the stronger of the 2 and would be a good choice if it was the only GPU in a rig.