Overclocked performance and power draw
Here's a quick look at the performance of the overclocked 655K and 875K processors compared to some other chips we've abused recently. Note that we had the Phenom II X6 at a base clock of 3.9GHz and a three-core Turbo peak of 4.3GHz.
At stock speeds, the Phenom II X6 1090T is only a smidgen slower than the Core i7-870. When the 875K and 1090T are both overclocked to their limits, the margin grows, and the 875K's lead is more pronounced. Remember, also, that we're seeing four Intel cores outperform six AMD cores at similar clock speeds.
One might expect the Core i5-655K's dual cores to have little chance against the quad-core competition, but its dizzying clock frequencies and strong per-clock performance allow it to close within striking distance. At 4.4GHz, the 655K trails the stock-clocked Phenom II X4 965 by only about five percentand the 655K is over 50% faster than the X4 965 in the single-threaded test. The only other processors to break the 6000 mark in the single-threaded portion of Cinebench are other overclocked 32-nm Intel CPUs.
Even at 4.4GHz, the 655K's power consumption is pretty reasonable; it draws about as much power under load as an Athlon II X4 635 or a Core i7-870and substantially less than a Phenom II X4 965. The 875K's power draw is much more considerable at 4.13GHz, but it's still lower than our overclocked Phenom II X6's. You'll need good cooling to get the most out of the X6 or the 875K.