Crucial MX300 275GB SATA III 2.5"

The Crucial MX300 hits 530 MB/s reads and 510 MB/s writes, which is as fast as SATA III gets, but that only lands it in the 25th percentile for speed overall. The real story is the 220 TBW endurance rating, well above average, and a 4.6 star average from over 12,000 reviews. It's a reliable workhorse for older systems, just don't expect NVMe performance.

Sequential reads hit 530 MB/s and writes hit 510 MB/s, which is about as fast as SATA III physically allows. You're not going to squeeze more out of this interface, and that's fine. The drive saturates the bus on both reads and writes, so if you're coming from a spinning hard drive, you're looking at a night and day difference. Boot times drop to seconds, apps open instantly, and file transfers stop being a coffee break activity.

Random performance is where things get more modest. 92K read IOPS and 83K write IOPS put this drive at the 42nd percentile for random operations. That's solid but unremarkable. The Dynamic Write Acceleration helps with bursty workloads by treating a portion of the TLC NAND as SLC cache, which gives you faster saves and smaller file transfers. But once that cache fills up, write speeds will dip. For a budget drive, this is expected behavior. The 220 TBW endurance rating is the real standout here, it's well above average and means you can hammer this drive with writes for years before it gives up.

Stacked against the Samsung 990 PRO, Lexar NM1090 PRO, or WD Black SN850X, this drive gets absolutely demolished on paper. Those are NVMe drives with sequential reads in the 7,000 MB/s range, over 13x faster than the MX300's 530 MB/s. But that's not a fair fight. Those drives need an M.2 slot and cost significantly more per gigabyte. The MX300 is a SATA drive for systems that can't take NVMe, or for people who just need a cheap, reliable boot drive. Against other SATA SSDs from its era, the MX300 holds its own thanks to the endurance rating and Micron's 3D NAND. The 275GB capacity is a bit odd, you get a little more than the typical 250GB drives, which was a selling point at launch.

Pricing is all over the place depending on where you look. The US listing shows $140, while the Canadian listing shows CAD 219. Neither is a bargain in 2025, but this drive isn't really being sold as new inventory anymore. The affordability score lands at the 64th percentile, which is decent but not spectacular. What you're really paying for is the Crucial brand reputation and that 220 TBW endurance rating. If you can find this drive used or on clearance for well under $100, it's a solid pickup for breathing life into an older laptop or desktop. At full retail, you're better off looking at newer SATA drives with more capacity.

The Crucial MX300 275GB is a SATA III drive that tops out at 530 MB/s sequential reads and 510 MB/s writes. Those numbers put it in the 25th percentile for speed in our database, which sounds rough until you remember this drive launched in an era when SATA was the standard. It's not competing with NVMe drives, it's competing with hard drives and older SATA SSDs. And against those, it still holds up as a meaningful upgrade.

What's more interesting is the endurance rating. Crucial rates this drive for 220 TBW, which lands in the 77th percentile for endurance. That's a lot of writes for a 275GB drive, especially one using TLC NAND. The 3D NAND tech from Micron helps here, and the Dynamic Write Acceleration gives it a boost on smaller transfers. The 92K random read IOPS and 83K random write IOPS are middle of the pack at the 42nd percentile, but for everyday tasks like booting Windows or loading apps, you won't feel the difference between this and a drive twice the price.

If you have an M.2 slot available, skip this entirely. The 25th percentile speed ranking means any modern NVMe drive will run circles around it for the same or less money. The 275GB capacity is also a dealbreaker if you're storing large files, games, or media. And if you're planning to clone your existing drive using the bundled Acronis software on Windows 10, be prepared for frustration. This drive makes sense for older SATA-only systems and budget-conscious upgraders who prioritize reliability over raw speed.

The Crucial MX300 275GB is a relic of the SATA era that still does its job. The 220 TBW endurance rating is genuinely impressive and the user sentiment score of 88/100 tells you that people who bought this drive are happy with it. A 4.6 star average across 12,011 reviews doesn't happen by accident. But the speed is capped by SATA III, the capacity is small by modern standards, and the bundled software is a known pain point. If you have an older system that needs a reliable SATA SSD and you can find this at a good price, it's a fine choice. If you're building anything new, look elsewhere.