Conclusion

With the Core i7 875K Intel makes the LGA 1156 platform even more interesting for overclockers and PC-Enthusiasts. Combined with a Triple-Channel memory-kit this CPU performs very well. The strength definitely are single-threaded applicaitons which is logical because of the Turbo-mode that boots this thing all the way up to 3'600 MHz. Therefore also working with a system based on a Core i7 875K is a pleasure. Furthermore this CPU is very energy efficient when in idle. Under load things are a bit different. In this case it burns almost as much energy as an X58 platform carrying a Core i7 920.

Thanks to the open multiplyer overclocking this CPU really is fun. Under these circumstances it really is possible to get a maximum of performance out of your system because you can now adjust CPU frequencies perfectly to BCLK and memory clock. The Core i7 CPUs out of the 800-series are also know for being exceptionally good to do memory overclocking.
Using a Noctua NH-D14 CPU cooler we were able to squeeze a bit more than 4'200 MHz out of our samples. This was also about what we expected the CPU would be capable of. At this point we have to add that the overclocking results can vary easily by 200 MHz when you do different trys with another CPU from the exact same series.

Another good fact about all the LGA 1156 CPUs is that a platform based on them is about a third cheaper in price than the LGA 1366 but still performs very well. This is because the motherboards cost less and you'll be able to buy dual-channel memory and you're not bound to more expensive triple-channel kits.

If you're looking for a LGA 1156 compatible CPU which you use mainly for gaming and overclocking then you'll be very well off buying a Core i7 875K CPU. But be aware the K-series really only makes sense if you do overclock your system otherwise there is really no difference at all if you buy a Core i7 870.