I recently got some new H-Die ddr4 memory chip from samsung this seems very promising. Like earlier Samsung 8Gb die it is very voltage tolerant and like over 2.1v, unlike earlier die it is ok with high VTTDDR voltage up around 1V. This is higher then Samsung B-Die and E-Die and D-Die which like around 0.85 - 0.95V in my experience. This memory chip like cold temperature and scale to around -110C, more cold allow for more temperature scale and less tRCD timing. tRP go below tRCD on viable platforms which allows for much better performance in less consistency workload. After a while of toying, on A2 G.Skill PCB I was viable to get to 5.2GT/s 12-13-13-28 2T. With a better board and cpu, 1T is possible since memory chip able to run 1T in memory down configuration at 5100 using 10980HK ES cpu (this cpu using R0 cpu die). This memory chip seems like might be best for tight timing bench-marking, only problem with this chip is it is very bad termination and signal integrity wise compared to hynix and micron options. With this chip, VREF like around 1.2V and go to around 1.32V under cold temperature with 8700K and Apex XI motherboard. This is quite low for VREF comparison to other memory chip which makes it bad for out of the box compatibility, though if you are able to tune termination to a good value IC has much capability. Due to bad signal integrity and dirty DQ output from memory chip buffer which is mainly architectural issue, this memory chip not very good for high memory clock speed, though that is not much problem since Samsung 8Gb E-Die is going to be released, which much like D-Die clocks high while being light on IMC. Even though it clocks high and is light on IMC it still is not good for signal integrity and has dirty output, this is just trait of samsung memory chip. For use such as server this will be very good memory chip, since it is least powerful samsung memory chip to date with IDD4R and IDD4W at 81mA and 73mA when operation at 2666V, due to this it is very efficient.