Introduction

Crucial's MX500 SSD Series was announced in December of last year and offers the first TLC-based SSDs that have convincing performance that's similar to what MLC drives provide. Our initial review was of the 1 TB variant, we reviewed the 500 GB version a few weeks ago, and today, we take a look at the M.2 version of the 1 TB MX500. Back when the MX500 was announced, only the 2.5" SATA versions made it to market and M.2 models became available just recently.

Just like the SATA models, the Crucial MX500 M.2 uses an SMI controller instead of the Marvell chips we saw on earlier MX-Series drives. It also uses Micron's own 64-layer 3D TLC NAND chips, which is a first for the company. While TLC chips provide cheaper cost per gigabyte over more traditional MLC NAND, they also come with lower write performance. In order to work around that, Crucial designates a small, variably sized amount of memory as SLC cache, which writes a single bit to each TLC cell instead of three. While much faster, such a setup is basically a speed vs. size tradeoff. According to Crucial, the SLC cache is variably sized to provide the best performance.

Unlike many other high-end SSDs on the market, the MX500 M.2 does not use the NVMe interface; rather, it uses the same SATA protocol as the 2.5" models do, which means performance should be pretty much identical to these, with M.2 adding the convenience of its form factor.