Sign in with
Sign up | Sign in

A PCIe Controller And Toshiba NAND

Plextor M6e 256 GB PCI Express SSD Review: M.2 For Your Desktop
By

Disconnected from the adapter card, Plextor's M6e is downright diminutive. Again, this is a 22 mm-wide, 80 mm-long device, which we expect to become a fairly common side for M.2-based SSDs moving forward.

In fact, unless you're reading this on a smartphone or tablet, you're probably seeing the front and back PCB shots larger than they actually are. M.2 storage can be 12, 16, 22, and 30 mm-wide, though most of what we've seen thus far conforms to the 22 mm standard, easily accommodating the width of NAND packages. An 80 mm length offers enough room for eight placements (four on each side). And if that's not enough for a specific application, PCBs can grow as long as 110 mm.

This is the second time we've seen Marvell's 88SS9183-BNP2 controller, too. Its first appearance was on SanDisk's aforementioned A110. The 88SS9183 rocks two native PCIe physical layers, which means it natively supports two second-gen PCIe lanes. That's fairly special functionality. Most of the PCIe-based SSDs we've tested were based on SATA processors alongside host bus or RAID hardware. After all, a modern RAID controller's job is connecting SATA or SAS storage to the PCI Express bus.

Marvell's implementation is essentially the same processor used in a great many SSDs with specific considerations for connecting through PCI Express. It's significant in that it's as low-power as we're used to on the desktop, and capable of exposing similar features.

The M.2 connector and Marvell's 9183The M.2 connector and Marvell's 9183

Next to the controller, we have Toshiba's 64 Gb Toggle-mode DDR manufactured on a 19 nm process. Again, that's the same flash found on Plextor's celebrated M5 Pro, rated for 3000 P/E cycles. We already know this stuff is fast. 

It's also worth a reminder that Marvell's 9183 controller and Plextor's firmware are in AHCI mode, supported by most modern operating systems without specialized drivers. The hardware does most of the things other SSD processors do, just over PCI Express. Differences to exist though, mostly with power consumption. DevSlp, for example, is a SATA command. The M6e should drop into a deep PCIe sleep state if the endpoint (that is, the slot Plextor's SSD populates) cooperates. We'll take a magnifying glass to power in just a bit.

Given the eight total NAND packages, we know each must employ a quartet of 64 Gb dies, totaling 256 GB. Plextor reserves just ~7% of that space for spare area.

Toshiba's NANDToshiba's NAND

React To This Article