StarTech.com M.2. PCI-e NVMe to U.2 (SFF-8639) Adapter - Not Compatible with SATA Drives or SAS Controllers - For M.2 PCIe NVMe SSDs - PCIe M.2 Drive to U.2 Host Adapter - M2 SSD Converter, TAA

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.

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.

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.

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.

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.

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.

YMMV but my Alienware R5 running Windows 10 Pro did not recognize a Samsung 960 PRO NVMe M.2 drive attached using this adapter. The Alienware has two U.2 connectors but the drive was not visible when attached to either one.The adapter seems very simple so it may be an issue with the computer -- all I can say is that the drive works great connected to the PCIe bus using Aquacomputer KryoM.2 PCIe 3.0 x4 adapter.