I intend to purchase a Icy Dock mb601vk-b disk hot-swap dock. This dock has an SFF-8639 (U.2) connector which is compatible with both NVME and SATA (What is U.2 SSD (formerly SFF-8639)? - Definition from WhatIs.com). Now I am already heavily invested in Icy Dock sata hot-swap drives (MB991 trays) so this seems like the perfect solution to retain compatibility with my existing stack of SATA drives and add NVME option.
The only question remaining is how to connect from the SFF-8639 to the motherboard. I have a spare M.2 slot that supports both NVME and SATA (so the slot accepts both M-key and B-key M.2). So if I connect from this slot to the icy-dock, I should have both SATA and NVME hotswap options in a single bay.
My question: Does such a adapter exists? From M.2 to SFF-8639 ánd supporting both SATA and NVME mode?
From what I have seen the NVME SATA drives there is very limited market for them only found a few at 500 GB capacity, I suspect most makers will focus on nvme pci-e is 4x speed on pice gen 3, gen 4 will be 8x as fast. In a few months, 2 and 4 TB pci-e will drop in price, from what I heard those icey adapters aren’t cheap you can probably already get 2 NVME pci-e drives that hold 2 or 4 times the compacity as the SATA version. If you have two pci-e drives mirror them should hold you over until you can a outage window to replace the bad one. More storage, more performance for less cost, simple drive swap after hours. What’s manager or bean counter complain about about this
I did do some more ´research´. The upcomming U.3 standard should support ´tri-mode´ on the same SFF-8639 connector (SAS, SATA and NVME) and has its data pins shuffeld. Where in U.2 the SATA(SAS0) and PCIe channels are actually on separate pins, in U.3 the first PCIe lane and the SATA lane are overlapping (like in M.2). With U.3, hot-swapping between SATA and NVME actually is a possibility, and this standard appears to be invented to exactly solve the problem I want to solve here.
Inside the M.2 connector the SATA and PCIe0 lanes are on the same pins, triggered by a pin that switches between SATA and NVME mode (so this will never work on a hotswap bay that doesn´t have the trigger pin, not even U.3 would work even while the data pins of SATA and NVME do align with M.2).
Eg. M.2 to U.2 or U.3 with SATA+NVME mode would never work because the enable SATA/NVME pin is never triggered correctly.
Only way remaining for now is one of those injectors that injects SATA+NVME into U.2 (because in U.2 the NVME and SATA data pins are actually separate physical pins, in contrary to U.3).
