We recently asked ASRock in the USA to reply with specific directions for doing a fresh install of Windows 10
on a RAID-0 of 4 x Samsung 960 Pro SSDs in an ASRock Ultra Quad M.2 card installed in an
ASRock X399M micro-ATX motherboard for AMD Threadripper CPUs.
They replied very promptly (same day) with the details.
The ASRock implementation looks very attractive, for several reasons of which I am aware:
(a) no need to "dangle the dongle" (cf. Intel VROC key);
(b) multiple Ultra Quad M.2 cards can be installed in the same motherboard (cf. DIP switches);
(c) the 6-pin 12V PCIe power connector is good planning;
(d) the cooling fan is larger than the comparable ASUS version;
(e) the diagonal placement of the M.2 SSDs should help with cooling;
(f) there is room for the longer 22110 M.2: Supports M Key type 2242/2260/2280/22110 M.2;
(g) it's now relatively easy to compare the performance of 4 x Intel Optane 900P, using the M.2-to-U.2 cable and adapter;
(h) our workstation needs a larger ramdisk, using RamDisk Plus, and a much faster RAID-0 is perfect
because our ramdisk is SAVED and RESTORED at shutdown and startup;
(i) other products are elaborating this storage "ecosystem" e.g. Icy Dock's 5.25" NVMe ToughArmor enclosure:
ICY DOCK ToughArmor MB699VP-B Rugged Full Metal 4 Bay 2.5" NVMe U.2 SSD Mobile Rack For External 5.25" Bay - Newegg.com
(j) a variety of M.2 NVMe SSDs can be installed in the latter, using Syba's U.2-to-M.2 enclosure:
SYBA SY-ADA40112 2.5" U.2 (SFF-8639) to M.2 NVMe - Newegg.com
(k) on-board installation of 4 x M.2 SSDs eliminates the extra expenses of cables and enclosures.
We've also requested ASRock to produce a YouTube video which demonstrates
Windows 10 installation on this AIC installed in the ASRock X399M motherboard,
like this video:
[ASRock Classroom] How to build RAID and install Win10 on M.2 SSD?
The essential functionality required of compatible motherboards is "bifurcation"
aka "4x4" in ASRock nomenclature, and x4/x4/x4/x4 in ASUS nomenclature.
Hope this helps!