Plextor blog walks you through the design process for the PX-M5S SSD: better, faster, cheaper

Plextor has just published an extremely interesting blog post that walks you through some of the high-level design decisions behind the company’s new PX-M5S SSD. According to the design goals, the prioritized objectives are:

1) speed
2) reliability
3) price

Then the blog post draws a line in the sand (silicon?):

“Plextor SSDs generally cost more than competing SandForce-based SSDs since they use a more expensive server-grade controller from Marvell, exclusive firmware, high quality flash memory from Toshiba, and surface mount components built by Japanese firms that settle for nothing less than obsessive tolerances.”

And finally, the blog post notes what’s different about the design of the PX-M5S SSD:

“The Plextor PX-M5S uses a different NAND supplier, and is priced more competitively than the previous M3 Series of SSDs, while still upping the bar in performance. For the M5S, Plextor turned to Micron to supply 25nm synchronous NAND flash, a product of equal quality to Toshiba Toggle NAND, but more available than the 24nm Toshiba Toggle Mode flash used on the M3S and M3 Pro.”

It’s extremely unusual for an SSD vendor to provide this level of insight into one of its designs yet the Plextor post continues in even more detail:

“Toggle technology is primarily used [manufactured] by Toshiba and Samsung, and carries data at a speed of 133MBytes/sec. In the ONFI (Open NAND Flash Interface) camp, the key manufacturers are Intel, Micron and Hynix… ONFI 1.0 (or Asynchronous NAND) is limited to a 50MBytes/sec transfer rate, but ONFI 2.0 (called Synchronous NAND) has a transfer rate of 133MBytes/sec. The key difference between ONFI 1.0 (Async) and ONFI 2.0 (Sync) NAND is its interface speed and, remember, speed counts with SSD users.”

Some of the specs for the SSD are pretty impressive including a sequential read speed of 520 Mbytes/sec and a sequential write speed of 200 Mbytes/sec. A 128GByte PX-M5S SSD lists at $149.99 on the Plextor site.

About sleibson2

EDA360 Evangelist and Marketing Director at Cadence Design Systems (blog at
This entry was posted in NAND, ONFI, SSD, Toggle and tagged , , , , , , . Bookmark the permalink.

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