Looking over the specs on the new RDS2216 I can think of a number of interesting use cases, but one constraint that jumps out is that the 20 NMVe slots are all 7mm (half-height) ones and almost all of the current crop of enterprise U.2 SSDs on the market are 15mm. In fact it's getting *really* hard to find 7mm models anywhere and they generally top out at 1TB

Does anyone know if I could use a 15mm U.2 drive and physically occupy two vertical slots, reducing the usable count to 10? (which is still not bad at 150TB raw with 15TB SSDs...) Noting that there's pretty much nothing else on the market with 10 U.2 NVMe slots under $2K.

The only ones able to answer that right now, work for Mikrotik.
Best to ask support.

U.2 disks generally starts from 960GB

there are plenty of 7mm options available:
https://help.mikrotik.com/docs/spaces/R ... isksforRDS

u.3 are also backwards compatible

untested, but size compatible:
Micron 7450 series
Transcend TS4TUTE210T
m.2 nvme inside m.2 to u.2 carrier - not recommended, but should also work.

edit

@antonsb - thanks for the link. I'm checking again, but on the Micron 7400 series for example, it's only the 960GB model that is 7mm. As soon as I go up to the 1.92TB I'm at 15mm.

Better luck with the Samsung 9A3/983 series which appear to go all the way up to 7.68 in 7mm.

I was originally looking mostly at Kioxia & Intel which are like the Micron and go to 15mm once you get bigger than 960GB.

I guess Samsung's getting my money (and Mikrotik of course)

Can anyone check if I can squeeze a 15mm model into two slots by removing the top caddy? Asking for the many others with the same question...

15mm is different part number:
https://www.microncpg.com/content/dam/m ... _brief.pdf

look for CB part for 7mm
MTFDKCB7T6TDZ 7.6TB
MTFDKCB3T8TDZ 3.8TB
MTFDKCB1T9TDZ 1.9TB

Can anyone check if I can squeeze a 15mm model into two slots by removing the top caddy? Asking for the many others with the same question...

I don't think that can physically work, the connector for the top one would block you inserting the drive far enough to engage the connector on the bottom one.

Interesting to see where this product line will go, I think a version supporting 10x 15mm drives with twice the PCIe bandwidth to each drive (4 lanes instead of two) would make a ton of sense and demand very little engineering effort. But I totally get why they wouldn't want to launch with two versions, the market for this is small enough as it is.

If this device can outperform regular intel xeon based box on mdraid performance + iSCSI - it will be a hit as inexpensive network flash datastore for virtualization. And if this device will support NVMEoF (NVME over RDMA) … Anyways we try to buy one and test as a networked iSCSI / NVMEoTCP datastore. But 7mm height is indeed a concern for future.

You can add Samsung PM963 to that list. I've also got some Micron 7300's coming in for testing.

I was able to use OWC’s M.2/U.2’s adapter, they’re 9mm tall. You do sacrifice the slot above the adapter, but they fit, and I don’t need 20 disks and only use 7 so all good for me.

In other words, 15mm should work as well, but you will likely have to sacrifice 2 slots for each disk you install.

Edit: after thinking about it, I think other commenters are correct, you will likely hit the U.2 connector right above your drive with a 15mm drive. I can only vouch for up to 9mm.

Edit 2: I can confirm 9mm is the max height. See pic.