Benchmarks: Memory
The use of DDR4-2,133 memory gives the Skylake platform a small edge over Broadwell, Haswell, Ivy Bridge and Sandy Bridge, all of which use DDR3 at lower speeds.
Of course, motherboard and memory manufacturers have already ratified much faster speeds than the JEDEC-approved 2,133MHz - we're seeing 3,600MHz support from the get-go, though whether the Core i7-6700K's integrated memory controller is up to the task of dealing with such sky-high frequencies is another matter.