For those, who need comparison data.
version 7 speeds:
7870 - 95 sol/s
7950 - 145 sol/s
7970 - 165 sol/s
270x - 100 sol/s
280x - 165 sol/s
285 - 110 sol/s
470 4Gb - 155 sol/s
My 7950 (Sapphire Dual-X) does more like 155 sol/s, but it's at 1050/1485. RX470 4GB from XFX does 160+ @1325/2025 and 480 Nitro 4GB does over 170 with 1340/2060, but I still have to mod bios on the Nitro.
Claymore for President!