I recently picked up a 2TB Samsung M2 SSD, but since installing it, I've run into quite a few problems. The most frustrating issue is that the read speed is capped at just 20MB/s. The drive's integrity is showing at 98%, which is reassuring, but I'm unable to update the firmware because Samsung Magician doesn't seem to recognize the drive at all. I attempted to install the firmware directly from an ISO, but that didn't work out either. I've even tried updating the drivers in the BIOS, but nothing seems to help. I'm really at a loss here and don't know what to do next.
3 Answers
Have you considered the possibility of a counterfeit drive? It might be worth checking the seller and the packaging to make sure everything looks legit.
If Samsung Magician can't recognize it, there's a good chance it's not an authentic Samsung drive. You could check the firmware version using a tool like CrystalDiskInfo to see if the drive matches up with what you're expecting.
Honestly, if you suspect it's fake, I’d recommend returning it. You shouldn't have to deal with this kind of performance issue from a new SSD. Better to be safe than sorry!

I bought it from a reputable site here in Brazil, and it all seems fine so far.