At first blush, the Crucial m4 seems virtually indistinguishable from its predecessor, the Crucial RealSSD C300. After all, it’s available in the same capacity with the same Marvell 9174 6Gb/s SATA controller and same amount of DRAM cache—256MB for the 128GB, 256GB, and 512GB versions, and 128MB for the 64GB drive.
What’s the difference between the Crucial m4 and a Micron RealSSD C400? Branding.
That isn’t to say the Crucial m4 is identical to the C300. For one thing, the m4’s firmware has been substantially updated from the sometimes-flaky firmware of the C300. For another, the m4 uses 25nm-process NAND, while the C300 used 34nm NAND. Smaller-process NAND means lower cost per gigabyte (thus, cheaper SSDs), but with a slight durability hit, albeit one probably unnoticeable to the end user.
In our tests, the m4 (and every drive in this roundup) positively smoked our best-of-the-best 3Gb/s SATA drive, the OCZ Vertex 2—sustained- read and -write scores as measured by Crystal-DiskMark and AS SSD were more than twice the Vertex 2’s scores, and the m4 scored higher 4KB random reads and writes across the board, from single-queue depth to QD 32. The 256MB of cache doubtless helped the m4 in PCMark Vantage’s HDD subtest, where it posted the highest score we’ve seen from a non–PCI-E drive. The m4 doesn’t have the fastest sustained speeds, but its random-access speeds are top-notch. And 400MB/s reads and 250MB/s writes would have been unthinkably fast a couple of months ago.
The Crucial m4 represents a great implementation of the Marvell 9174 controller, and a great demonstration of the advantage of native 6Gb/s SATA.
Great random-access speeds; 400MB/s reads, 250MB/s writes.
Not the fastest.
Sustained Read (MB/s)
Sustained Write (MB/s)
4KB Read, 32QD (MB/s)
4KB Write, 32QD (MB/s)
Seq. Read (MB/s)
Seq. Write (MB/s)
4KB Read (IOPS)
4KB Write (IOPS)
Read Access (ms)
Write Access (ms)
64KB File Read (MB/s)
64KB File Write (MB/s)
4KB Random Write
Max Access Time (ms)
Premiere Pro Encode Write (sec)
PCMark Vantage x64 HDD
Our current test bed is a 3.1GHz Core i3-2100 processor on an Asus P8 P67 Pro (B3 chipset) running Windows 7 Professional 64-bit. All tests used onboard 6Gb/s SATA ports with latest Intel drivers, except 3Gb/s SATA tests, which used onboard 3Gb/s Intel SATA ports.