Plextor M3 256GB
Introducing Plextor as an SSD maker in our reviews, we should perhaps start with the M2S series which was the company’s first mass-produced SATA 6 Gbit/s SSD series but it’s too old already and we couldn’t find a sample. Moreover, the newer M3 series isn’t much different, using the same controller Marvell 88SS9174 together with Toshiba’s Toggle Mode flash memory.
The Plextor M3 looks like a very typical SSD. Its brushed aluminum case has rounded corners and a standard height of 9.5 millimeters. The surface is anodized a little. The manufacturer's logo is painted in white on the face panel. On the other side, there is a sticker with part number, manufacturer info, barcode, serial numbers and other not-very-useful service information.
The case contains a PCB with a Marvell 88SS9174 controller, which is revision BKK2, and eight memory chips labeled TH58TEG7D2HBA4C. These are 24nm NAND MLC chips with Toggle Mode interface. Considering that this is a 256GB model, each chip contains four 64-gigabit semiconductor dies, so the eight-channel controller can use 4-way interleaving on each channel.
It must be noted that Plextor was one of the first manufacturers to start using 24nm flash from Toshiba. Such memory has by now become a trendy choice for SandForce-based SSDs but the Plextor M3 series was released a year ago when 24nm Toshiba flash was new.
Besides the controller and flash memory chips, Marvell-based SSDs feature an SDRAM buffer. The 256GB Plextor M3 employs two DDR3-1333 chips Nanya NT5CB128M16BP-CG which combine into a 512MB cache. Lower-capacity M3 series SSDs have a proportionally smaller cache.
Plextor M3 Pro 256GB
We must confess that the real reason for the M3 Pro series is a mystery to us. It was rolled out only two months after the M3 and didn’t differ from the latter. Of course, the manufacturer claimed higher performance, but not through any hardware improvements. Firmware optimizations were supposed to make the Pro version faster.
From the hardware aspect, the M3 Pro series can only boast a 7mm case which fits into ultraportable notebooks. The case design is the same as in the M3 series, just slimmer and without any anodizing.
The PCB is the same, too. It even has the marking of the simpler series. There are almost no differences in terms of components, either, except that the Pro series features the newer and more popular revision BLD2 of the Marvell 88SS9174 controller. The rest of the components, including the SDRAM buffer and flash memory, are identical to those of the ordinary Plextor M3, but for marketing reasons the M3 Pro model range is different and does not include a 64GB model.
Notwithstanding the internal similarities, we do not know if it is possible to transform an ordinary M3 into an M3 Pro by rewriting firmware. This operation may be impossible due to limitations imposed by the manufacturer or to the difference in the controller revisions.