Samsung 1TB SSD PCIe 3.0 x4 NVMe M.2 2230

The PM991a is the boring, reliable 1TB upgrade your Steam Deck deserves. It won't win speed contests, but it fits where other drives can't.

The random read performance is the quiet star here. At 380K IOPS, it lands in the 84th percentile, which means app launches and game loads feel snappier than the sequential numbers suggest. The write side is more modest at 330K IOPS, and sustained writes will dip once the TLC cache fills. For a Steam Deck, that's a non-issue. For a workstation, you'd feel it. The endurance rating is the real weak spot, sitting near the bottom of the barrel at the 15th percentile. This is not a drive for heavy write workloads.

Against the Crucial T500 or WD_BLACK SN850X, the PM991a gets smoked on sequential speeds and endurance. Those are Gen4 drives with double the throughput and much better write durability. But they're also 2280 form factor, which means they won't fit in a Steam Deck or Surface without an adapter that doesn't exist. The Micron T710 is the closest real competitor in the 2230 space, and it trades blows with the PM991a on random performance while offering better endurance in some configurations. If you can find the Micron at a lower price, it's worth a look. If not, the Samsung is the safe pick.

This is a tough one. At around $249 USD for 1TB, you're paying a premium for the 2230 form factor. The same money gets you a 2TB Gen4 drive in the standard 2280 size. But if your device physically cannot fit a 2280 drive, the PM991a is one of the better options available. You're paying for compatibility, not performance. That's the deal, take it or leave it.

The Samsung PM991a is the drive you buy when nothing else fits. It's a 1TB M.2 2230 NVMe stick that slots into the Steam Deck, Surface tablets, and a handful of ultrabooks that demand the tiny form factor. You're not buying it for speed records, you're buying it because it's one of the few 1TB options in this size that doesn't suck. And it mostly doesn't suck. Sequential reads hit 3100 MB/s, which is fine for PCIe 3.0, but the 1400 MB/s write speed tells you this is a practical drive, not a show pony.

If you're building a desktop or have a laptop with a standard 2280 slot, skip this entirely. You can get a 2TB Gen4 drive with better endurance for the same money. The PM991a only makes sense when the 2230 form factor is a hard requirement. If you need serious write endurance for content creation or heavy workstation use, this isn't your drive. Go grab a WD_BLACK SN850X or Crucial T500 instead.

Buy the PM991a if you need a 1TB 2230 drive and you want something that just works. It's not the fastest, not the most durable, and definitely not the cheapest. But it's reliable, widely available, and the random read performance keeps everyday use feeling quick. For Steam Deck owners specifically, this is one of the best upgrades you can make. Just don't expect it to impress anyone in a benchmark screenshot.