DDR4 has certainly ramped up the frequencies but as we have seen with previous generations of RAM, the timings tend to get looser as that frequency increases.  Take for example Crucial's 16GB DDR4-2666 kit which sports timings of CAS 16, tRCD 17, tRD 17 and tRFC 36.  Indeed to overclock the RAM to 2808MHz, Bjorn3D had to change the timings to 19-17-17-36, however at that speed it nosed slightly ahead of the Patriot kit running at 2800MHz @ 16-18-18-36 so tweaking this RAM can pay off and the Crucial Ballistix MOD Utility will let you know if you are getting into Kenny Loggins' areas.  At $170 it will not break the bank and it will beat out at least some of the competition in performance, albeit by a very slight margin.

"In this review we are going to be looking at one of the many DDR4 modules that Crucial offers for the 2011v3 CPU platform: the 2666Mhz 16-17-17-36 16GBs DDR4 Ballistix Elite Memory. So step inside and see how this memory stacks up."

Here are some more Memory articles from around the web: