As computing moves to ever-shrinking desktop form factors, slow 2133 MT/s and 2400 MT/s DDR4 memory becomes less acceptable. Folks who demand the absolute top performance from their systems can't neglect memory performance, but until fairly recently there just weren't many high-performance SO-DIMM kits. Corsair is among the companies turning that around, and the nautically-named group just released what it says is the fastest 32 GB DDR4 four-stick SO-DIMM kit ever at 4000 MT/s.
There aren't many systems using SO-DIMMs that can even run their memory at that screaming speed—much less four sticks' worth. Corsair remarks that this kit is specifically intended for small-form-factor machines based on Intel's X299 platform using motherboards like ASRock's X299E-ITX/ac. The company describes the RAM's 19-23-23-45 timings as "super tight," and remarks that the sticks will need to run at 1.35 V to do their thing.
As Corsair itself points out, 4000 MT/s is well into the range of overclocking for DDR4 memory. The company says it hand-picks the best Samsung B-die chips for these sticks. Dedication like that should help guarantee reliability, but it also means these modules aren't going to go cheap. The memory is currently only available at Corsair's site, and it'll run you $595 for the four-module kit.