I'm fairly certain a lot of people have spare NVMe SSDs of varying capacities, as one upgrades or accumulates more from sales. Modern motherboards don't have enough M2 slots to accomodate all of these drives, so they're not being put to use. And I don't think they have figured out to put the M2 connectors sideways so the drives can be stacked similarly to RAM. But what most existing motherboards do have is a lot of SATA connectors. My x570 has 8, and both of my itx b550s have 4.
So what I would like, would be an enclosure that is the same exact size as a 3.5" HDD that will fit inside of drive bays of a PC case. A 3.5" HDD draws 6-10W, and peaks at 25W. 2280 is about 5.5W, less while idling. So one SATA power cable should deliver enough to power all four SSDs. And it wouldn't require having to use an electrical plug, like every 3.5" external enclosure requires. I would like for it to connect to and use 4 separate SATA data cables as well. No software, no compability issues with mixing PCIe, all drives are individual. This would free up the USB ports that external enclosures require. It wouldn't block fans like PCIe adapter cards. It would be the same speed as existing USB 3.0 enclosures, so the 550-600 MB/s limit isn't an issue.
@DT MDR For multiple M.2 NVMe SSDs we sell add-in cards that can take up to four drives, either requiring board PCIe bifurcation (EC-P4BF) or not (EC-P3X4). PCIe NVMe SSDs won't work with SATA as M.2 uses 3.3V only and SATA SSDs use 5V. SATA power can deliver 3.3V/5V/12V but this is cumbersome. Also, the SATA interface is not directly compatible with PCIe, which is why there was SATA Express (SATAe). However, U.2 could accommodate the 2.5"/3.5" form factor, although an adapter is required for boards with only M.2, and an AIC would be required for more.
If you happen to have a free PCIe slot that's x4+ electrically, and x4+ physically, the EC-P3X4 is a good solution. You could get creative with this using a riser. The nominal 25W of a PCIe slot is plenty given the bandwidth restriction. There are probably other solutions that could use USB headers and the like, but not as elegant.
This was an interesting product that never saw the light of day (at least from Kingston): https://www.anandtech.com/show/12340/kingston-unveils-dcu1000-four-consumer-m2-ssds-in-a-u2-enterprise-drive. In a nutshell, it crammed 4 M.2 2280 SSDs into one 15 mm 2.5″ U.2 enclosure.
It turns out these were being made by a different company, which has since stopped making them for at least two years. Some eagle-eyed individuals have gotten them off eBay and tested them. They run very hot, so at the 2.5″ size it’s pretty much proven to be a bad idea.
Can’t say for 3.5″, which a certain competitor of Sabrent does make—but it’s practically useless outside of their ecosystem of removable SSDs and direct-attach U.2 cables.
@Kevin Li We do offer a U.2 adapter (EC-U2SA) now, so we are exploring other interfaces but I don't think we have anything that ambitious currently planned. We have looked at docking stations and bays for M.2, at least.
I just stick mine in RAID arrays. It's not pretty but it works. They only claim they support up to 512gb SSDs but I have both 1 & 2tb drives that work just fine.
