My friend has crossfire 7950's while I have a GTX 670 2GB PE. I can't seem to find any benchmarks for this, since the only benchmarks are for SLI so I was just wondering what is the difference in performance between the 2.
same thing even with 7950s, in terms of benchmark scores like 3DMark11 even 2 7850s will beat a single 680 by about 100 points or so. Basing off this two 7950 will absolutely destroy a single 670, especially when overclocked and factoring in 384-bit bus, 3GB memory, etc...
If the resolution is 1080p like i said and at 60hz, the difference is minimal, a 670 gtx can maxout most of the games at that resolution.
But just for fps wise sake, two 7950 will get much more, but if you put another 670 gtx, it will be bested.