StarTech.comU.2 to M.2 Adapter - for 1 x U.2 PCIe NVMe SSD - M.2 PCIe x4 Host Interface - U.2 SSD - M.2 PCIe Adapter - U.2 Drive , TAA (M2E4SFF8643)

U.2 may be dead in the consumer space, but using this adapter we're able to convert the port to a standard M.2 port, since both use PCIe protocol natively. Now I can have 3x M.2 drives on my system natively!I'm pleasantly surprised to see full PCIe 4.0 x4 speeds through this adapter. My U.2 slot goes through the chipset (AMD WRX80), so 6.4 GB/s is about the max we can get. PCIe 4.0 U.2 ports connected directly to the CPU can get up to 7.5 GB/s. This adapter is simple and gets the job done.I do wish some kind of heat sink material was included with this adapter, as PCIe 4.0 M.2 drives tend to run hotter. But probably a non-issue unless you're hammering the M.2 drive with constant IO. Just mount this somewhere near the front of the case so the drive can get some airflow.

I have a bunch of 250GB NVMe SSDs pulled from Dells. I figured I'd repurpose them for some older computers that don't have NVMe slots, so I bought one of these to test, with the intent to connect the NVMe drives to the older computers' SATA ports. Lo and behold, these don't have standard SATA connectors, they have SFF-8639 connectors, which are typically used by SAS drives (server-oriented). So, forget about connecting these to standard SATA controllers; you need to connect a RAID controller with a SFF-8639 breakout cable. The especially irritating thing is that SATA drives are compatible with SFF-8639 cables, but SFF-8639 drives are not compatible with SATA cables. IE, if this adapter had a SATA connector, you could use it with SFF-8639 cables AND SATA cables, but since it's SFF-8639, it will only work with SFF-8639 cables.Now, to be fair, it is entirely my fault for not being positive that this adapter was the right thing for my needs. My one-star rating is because I can't think of any practical reason to make an adapter that simply doesn't work with SATA cables and only SFF-8639.

a bit quirky to put together but works well with the drive once installed.

Since the world has conspired to bring us motherboards packed with several M.2 slots and NVME which is piggish with PCIe lane usage, this adapter allows one to use these pre-allocated lanes for something more sophisticated than the simple, low-endurance M.2 SSD. The average user would be shocked to learn that M.2 SSD drives are expensive, low endurance, and low capacity compared to the u.2 offerings. Why the world is going along with this fisher-price technology, M.2, is beyond me. At least with this adapter we can leave the children, and their child-like SSDs behind.

It seems that the m.2 ssd using this adapter cannot be the boot device of the operating system on Dell's R640 server. I have tried to install almalinux9.4 on the m.2 nvme ssd of this adapter many times, but every time the installation is completed and the server is restarted, I can't boot into almalinux normally.

Here is a fine product...even better if you get the right one. My point here is be careful to buy the correct adapter (and probably the SSD for it). I bought the listed unit before I opened the case on my laptop to check the plug type I had. I bring this up because I am a tech and should have known better ! My own machine, for Pete sakes and I messed up. These adapters are great, replacing the old mechanical drives. Of course it’s gotta be the correct one. The moral to the story ? This is an excellent adapter, nice and fast...a perfect compliment to the SSD assuming you get a nice fast SSD. Look ma ! No moving parts except for the fans.

Anyone who leaves negative reviews on this product about it not working in their SAS server or with SATA drives really needs to STFU and stop tinkering with hardware they don't understand.This product adapters the M.2 form factor to U.2, while leaving the signals intact as-is. Its a plug adapter, essentially. You will need a PCIe endpoint to plug this into, like a bifurcation card with the correct SFF ports.Anywho, using this product with a Samsung 980 NVMe drive in my Dell R720 after upgrading on of the bays with a U.2 backplane + PCIe bifurcation card = great success.

This worked when I first installed it and thereafter for 2-3 weeks. Then I removed the drive it was connected to so I could fresh install Linux without affecting the SAS drive. It never worked again. Put it in different m.2 slots to make sure and it didn't work. Sometimes populating an M.2 can disable a PCIe slot or vice versa (check your motherboard manual) so I removed everything but this adapter and drive - no luck. Then I put the SAS drive on a PCIe card adapter and it works fine. So, this handy little adapter bit the dust but my drive still works (yea!). It's a shame because I'd prefer this method to taking up an extra PCIe slot. I think this is the first negative I've ever had with StarTech, usually have better luck. I assume all these type adapters are flakey, not just from StarTech.