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Crucial M550 review

Crucial M550 1TB
Our Rating :
Price when reviewed : £370
inc VAT

A very fast SSD at a great price, but the Samsung 840 Evo is just a bit faster


Capacity: 256GB/512GB/1TB, Cost per gigabyte: £0.46 (256GB), £0.42 (512GB), £0.38 (1TB)Interface: SATA3, Claimed read: 550MB/s

The MX100 is Crucial’s budget-friendly SSD, but this M550 exists for those who value extra performance. Unlike Crucial’s cheaper model, the M550 is available with up to 1TB of storage. The M550 is the successor to the M500, one of our favourite SSDs. As its name suggests, the M550 is a relatively minor update, but any drive that improves on the excellent M500 is fine by us.

Along with the 1TB drive, you can also buy 256GB and 512GB versions. All except the 1TB model are available as standard 2.5in SATA3 disks and as mSATA DIMM-style chips for use in Ultrabooks. We stuck to testing the 2.5in SATA3 version, but there shouldn’t be any performance differences between the two form factors.

Crucial M550 1TB

Like the MX100, the M550 isn’t available as part of an upgrade kit with cloning software, a USB to SATA adapter or other accessories. All these bits are widely available elsewhere, though, and a bracket for mounting the 7mm-thick SSD in laptops with 9.5mm disk bays is at least included.

The M550 uses 20nm Micron NAND flash, much like the M500, but with a new Marvell 88SS9189 controller with custom Micron firmware. All the different M550 capacities performed comparably in our file transfer speed tests.

With the 1TB model, large files were written at 617MB/s and read at 618.2MB/s, which are very fast speeds indeed. Small files were written at 100.1MB/s and read at 83.5MB/s, which is above average.  When testing the 256GB model, we saw large-file speeds of 628.5MB/s write and 610MB/s read and 100MB/s write and 81MB/s read in the small files test, so there is little performance difference between the capacities.

Crucial M550 1TB

The 1TB drive is the best-value drive per gigabyte, costing 38p per GB, but £382 is a considerable amount of money to part with. The 512GB drive is 42p per GB and the 256GB model is 46p per GB, making them both good value for such quick drives.

The M550 isn’t the cheapest SSD, but is still good value and has excellent file transfer performance. It wins a Best Buy award. For all our current best Buy SSDs see our regularly updated Best SSD article.

Cost per gigabyte£0.46 (256GB), £0.42 (512GB), £0.38 (1TB)
Claimed read550MB/s
Claimed write500MB/s
ControllerMarvell 88SS9189
NAND flash type20nm MLC
Mounting kitNo
Buying Information
WarrantyThree-year RTB
Part codeCT256M550SSD1

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