Intel Core i7-6700K Review: Inching Toward Extreme

Clock-for-Clock Comparison vs i7-4770K and i7-5775C @ 4GHz

Stock is one thing, but to gauge how well the new generation CPU actually performs over the last in terms of CPU performance, there must be parity, so the processors were set to 4GHz and memory was set to 1600MHz 11-11-11-28-1T and then 2133MHz 11-11-11-28-1T to check for performance improvements and cache was locked to default values. While DDR3 memory default is 1600MHz, DDR4 support defaults at 2133MHz in Skylake and can generally run much higher frequencies than DDR3 platforms. All other settings remain to defaults. I would have liked to include higher overclock comparison (4.5GHz) and higher memory frequency (2666MHz) but the i7-5775C is a poor overclocker and its IMC cannot run DDR3 that high so 4GHz with 1600Mhz and 2133MHz memory would have to do.  The graphs are set in order of generation with the oldest at the bottom.

AIDA64 CPU and FPU performance @ 1600MHz (top) vs 2133MHz (bottom):

Cinebench R15 @ 1600MHz (left) vs 2133MHz (right):

WinRAR @ 1600MHz (left) vs 2133MHz (right):

x.264 FHD @ 1600MHz (left) vs 2133MHz (right):

Benchmarks show just how much DDR4 chokes when lower than 2133MHz and all three CPUs are set to the same clocks. Just look at WinRAR which makes use of memory quite well and even takes advantage of the i7-5775C’s eDRAM. At 2133MHz, the i7-6700K is bested (albeit by a hair) by the i7-5775C. Surprisingly, the i7-6700K did not take the rest of the performance crown as expected either taking a backseat on the CPU tests, notably CPU queen, Photoworxxx and Z-Lib but shows linear progression in the CPU Hash benchmark, Cinebench R15, WinRAR and x.264 with superior FPU performance in AIDA.