I bought an absurdly cheap nvme from eBay. It’s labeled as pm981 1TB, which is meant to be some Samsung oem disk.

I’m currently using it as zfs mirror disk.

It seems to do the trick and haven’t had any issue so far. I’m wondering though whether it’s even real and not some fake product.

Is there any way to check out whether the disk is faulty / speed / reliable / etc?

Often things to good to be true are just faulty…

Looks as the PM981 usually is OEM for several brands of business laptops. Given the capacity, age and being a PCIe 3.0 drive, it isn't really a high price item these days.

You don't say if it was sold as new or used, or who the aBay seller was. Many business laptops are leased, when returned are sold off to refurbishers who then put them for sale on eBay. Many of the refurbishers will install a new drive in the computer, so not to worry about drive failures costing them money or negative feedback. They then have a second storefront, which they will sell miscellaneous parts.

My gut says it is likely a legit Samsung drive. You can get a feeling by looking at the seller and listing, to see how legit the seller may be.

It was sold as "new", but who knows...

As you said, I wasn't overly suspicious as it is old, old technology, and OEM. I was looking to buy 2.5" SATA SSD disks and realized how expensive they still are although equally oudated technology. Was surprised the SATA disks are as expensive as modern NVME disks. That triggered my thinking that the PM981 disks were too cheap to be authentic. Well, maybe just got lucky.

I just installed diskspeed docker and giving this a shot. If this passes at solid speed, I'd assume they are just old and potentially refurbished of some form. But at least not fake. And given I am using it as a ZFS mirror disk, the worst is that it fails and then I just replace it.

It could potentially be new (NOS). Could be old, unneeded inventory from a company's IT/service department for repairing employee's laptops.

I have worked in a computer service department before. All sorts of brand new, unused parts for computers that were new more than a dozen years earlier. Eventually you need to get rid of them, especially in localities which charge a tax on the company's inventory.

You are correct, doesn't seem the risk to you is very big. Run it until it won't, have a plan for replacement when it does. I have a 120GB SSD in my server, was the very first SSD I ever bought. It has been in at least a half dozen systems, it just won't die. I use it as a Plex transcoding temporary file drive now.

Got it, this makes sense to me. So could even be a good deal. Same as you, I also still have a 120GB SSD, which must be one of the very first generations and must have cost a fortune. It obviously is totally outdated technology by now, but I keep using it for time to time to try out new things. For example, I just thought about using it to convert one of my VMs to a barebone install.

The diskspeed docker doesn't work to test the PM981 as it doesn't work for ZFS pools. But it seems for this exchange that it may well be an authentic - though very old - disk.