iballew :
According to multiple websites, the 860k is slightly more power efficient while the 760k has 100 mhz faster clock speed. Otherwise, there is no significant difference. Am I missing something?
The 860K is steamroller architecture, the 760K is PileDriver architecture. The 860K has numerous important refinements. Twice as many instruction decoders and the addition of a loop buffer removes the vast majority of the MP scaling penalties of PileDriver, which by itself is a major factor here, as it means that in MP workloads, a 4 core steamroller will be able to achieve the instruction performance near that of a 6 core PileDriver in some cases. Almost all noteworthy instruction penalties and denormal penalties in PileDriver have been reduced or eliminated in Steamroller, as well as better handling of 256bit operations (in some cases up to 8X better than piledriver), up to double the FMA3 instruction throughput, larger L1 caching, improved L2 cache performance (lower latency, better buffers, up to double the write bandwidth)...
Bottom line here is that there's no good reason to buy a 760K at this time. The 860K is already showing 10-30% performance advantages over the 760K in existing software. That doesn't take into account what happens as compilers are modified to take advantage of more of what Steamroller has to offer.
http://www.cpubenchmark.net/cpu.php?cpu=AMD+Athlon+X4+760K+Quad+Core&id=1997
http://www.cpubenchmark.net/cpu.php?cpu=AMD+Athlon+X4+860K+Quad+Core&id=2362
The improved compute efficiency is just icing on the cake IMO.