Best 128GB Crucial MLC SSDs
There are 7 128GB Crucial MLC SSDs compared here. The fastest is the Crucial BX300 at 555 MB/s read. Sequential reads across the group span 500–555 MB/s at 128GB.
Why this configuration
A 128GB Crucial MLC SSD is a legacy endurance choice. MLC stores two bits per cell instead of three, so these older drives take far more rewriting than a modern budget drive, at a much higher cost per gigabyte. Crucial specifically tends to be chosen here for its firmware track record and warranty support.
At 128GB this is really a boot or cache drive rather than a main library.
Usually chosen for: write-heavy secondary roles and keeping older machines useful.
Good fit: mainstream desktop and laptop builds.
Ranked list
Speeds on this page are the manufacturer's 128GB ratings where published (4 of 7 drives), not the family headline figure. Rated writes at 128GB run 150–350 MB/s.
| # | Model | Tier | Controller | Read MB/s (at 128GB) | TBW | |
|---|---|---|---|---|---|---|
| 1 |  Crucial MX100 128GB, 250GB, 500GB | High-end | Marvell 88SS9189 | 550 | 72 | Find on Amazon |
| 2 |  Crucial M500 128GB, 250GB, 500GB, 960GB | High-end | Marvell 88SS9187 | 500* | 72 | Find on Amazon |
| 3 |  Crucial BX300 128GB, 250GB, 500GB | Mid-range | Silicon Motion SM2258 | 555* | 160 | Find on Amazon |
| 4 |  Crucial M550 128GB, 250GB, 500GB, 1TB | Mid-range | Marvell 88SS9189 | 550 | 72 | Find on Amazon |
| 5 |  Crucial M550 mSATA 128GB, 250GB, 500GB | Mid-range | Marvell 88SS9189 | 550 | 72 | Find on Amazon |
| 6 |  Crucial BX100 128GB, 250GB, 500GB, 1TB | Mid-range | Silicon Motion SM2246EN | 535* | 72 | Find on Amazon |
| 7 |  Crucial M4 128GB, 250GB, 500GB, 64GB | — | MARVELL 88SS9174-BLD2 | 500 | 72 | Find on Amazon |
* family rating — the manufacturer does not publish a 128GB figure for this drive.
The parts, explained
128GB suits a boot drive or a light secondary disk.
MLC NAND is older and costs more per gigabyte, but is very durable.
Staying with Crucial means consistent firmware, tooling and warranty handling across the range.