Plextor M7e PCIe SSD to Ship in Q3, M7V TLC SSD in 2016 & New Software Features

Plextor first showed off the M7e at CES earlier this year and at Computex we got an update on the release schedule. Plextor is now aiming for Q3 release, meaning that we will likely hear the final release at Flash Memory Summit in August. Specifications have not really changed since the M7e still utilizes the same Marvell PCIe 2.0 x4 AHCI controller with performance rated at up to 1.4GB/s read and 1GB/s write as well as up to 125K random read and 140K write IOPS. M7e will be available in both M.2 and PCIe card form factors with capacities range from 256GB to 1TB, so the M7e may very well be the first M.2 2280 drive to break the 1TB barrier. 

Regarding the TLC drive M6V (or M7V as Plextor now calls it), Plextor is taking its time to fine tune the firmware to squeeze every megabyte of performance out of the drive and more importantly ensure high reliability and endurance. Plextor told me that its firmware can boost the endurance to 2,000 P/E cycles with 15nm TLC, so it the claim holds true then I’m fine with Plextor taking a little longer and pushing the release to 2016.

On the software side, Plextor actually had three new items to show. The first one is updated PlexTurbo, which now carries version number 3 and increases the maximum cache size to 16GB. The cache size is also now user adjustable and supports multiple disks, so one can decide what Plextor SSD to speed up with PlexTurbo.

The first new addition to Plextor’s software suite is PlexVault, which creates a hidden partition for storing sensitive data. The partition is completely hidden and isn’t even visible in Disk Management, so other users won’t even know that such hidden partition exists. Accessing the partition works through a hot key, although a password can also be entered to protect the hidden partition from accidental access. I’m not sure how useful the feature really is, but I guess it creates another layer of security for NSFW (not safe for the wife) content for those who may need it. 

The final piece of new software is PlexCompressor, which is an automated compression utility. If a file is not accessed for 30 days, PlexCompressor will automatically compress the file to increase free space. The file will then be uncompressed when accessed, which obviously takes a bit of the free space since the file will now be stored in uncompressed format for another 30 days. The compression is transparent to the user and is done fully in software (i.e. by the CPU), so it’s not SandForce-like hardware compression. There is no impact on SSD performance, although as compression consumes some CPU cycles there may be impact on CPU heavy workloads and especially battery life. Out of the three pieces of software Plextor has, I think PlexCompressor is the most potent because it results in concrete extra free space for the end-user and with SSD prices still being relatively high (compared to HDDs) it makes sense to get the most out of the storage one has.

SFF-8639 Connector Renamed as U.2

As SATA Express never took off because of the two-lane limitation, the SSD and motherboard industries have been looking for an alternative connector for connecting 2.5″ SSDs over PCIe. SFF-8639, which is essentially SATA Express on steroids with support for four PCIe lanes, has been viewed as the most potent connector because it already has industry support in the enterprise space and with the SSD 750 Intel brought the SFF-8639 connector to the client side. Given that SFF-8639 isn’t a very consumer facing name (even I’ve had trouble remembering the numbers), the SSD Form Factor Working Group has decided to rename the connector as U.2 to make it more marketable. That coincides well with M.2 that has already been used in the industry for a couple of years and more importantly both connectors now carry alike naming.

Whether U.2 and 2.5″ PCIe SSDs take off in the client space remains to be seen, though. The biggest hurdle is the expensive cabling because unlike normal SATA and SATA Express cables, the U.2 cable consists of several small, shielded cables that increase the cost. From what I have heard that is the reason why the industry came up with SATA Express in the first place because the OEMs wanted to keep the cabling cost equivalent to existing SATA cables.

I believe M.2 will be the main connector / form factor in the client space, but there is still a market for high performance and capacity 2.5″ PCIe SSDs as M.2 has more physical limitations that restrict the capacities and thermals. I can see U.2 in high-end motherboards where the connector and cable costs aren’t that big of an issue, but we’ll see what happens over the next year or two.

Source: Hardwarezone via PC Perspective

Seagate Announces SandForce SF3500 SSD Controller Series: Mass Production Expected in Q4’15

The SandForce SF3000 series has become the unicorn of the SSD industry. For the past two years there has been a lot of hype about the new controller, but Seagate/SandForce has kept missing deadlines one after the other. Initially the third generation SandForce controller was supposed to ship in mid-2014, but obviously that didn’t happen. Next we heard Q4’15, which was then changed to mid-2015 and the latest word I got at Computex is expected mass production in Q4’15, meaning that we could see first products shipping in early 2016. 

The SF3500 package is considerably smaller than the SF3700

The original paper launch back in late 2013 only included the SF3700 lineup, which was first supposed to cater all markets from entry-level client to enterprise. Last week Seagate announced that the SF3000 series has now been split into two: SF3500 for the client and SF3700 for the enterprise market. The reasoning behind the differentiation doesn’t only lie in marketing as the SF3500 and SF3700 are separate dies with the SF3500 having four NAND channels whereas the SF3700 keeps the 9-channel design as announced previously. It makes a lot of sense to build a separate die for the client space and honestly I was a little skeptical about cost efficiency because it’s practically impossible to build a silicon that is feature rich enough for the enterprise with a consumer friendly price tag. We’ve seen the client space moving towards 4-channel controller designs anyway, so I suspect introducing a smaller 4-channel controller was the only way SandForce could remain price competitive against Silicon Motion, which has taken a large share of SandForce’s old clients. 

The SF3500 series includes three SKUs and similar to the SF3700 silicon the controller supports both SATA 6Gbps and PCIe 2.0 (although only two lanes, whereas the SF3700 features four). The SF3514 and SF3504 are SATA and PCIe respectively, but the SF3524 has a switch that allows it to operate in both SATA and PCIe modes similar to the SF3700 SKUs. Unfortunately the switch isn’t user-accessible as it has to be toggled by the manufacturer, so it’s merely a feature that helps the OEMs with inventory management. The SF3524, being the high-end model, also has more supported firmware features, but Seagate isn’t disclosing any at this stage, although I was told they are more back-end related rather than concrete features that are visible to the end-user. 

Inherently the SF3500 is just a 4-channel version of the SF3700 and supports all SandForce technologies (DuraWrite, SHIELD, RAISE etc), but with one twist. The SF3500 is the first time SandForce is relying on external DRAM for caching the NAND mapping table, whereas the SF3700 and all older SandForce controllers only use the integrated SRAM. No user data is stored in the DRAM, so its function is purely to increase performance as well as reduce power up time when waking the system from sleep. 

Another separating feature is the RAISE support. Because the SF3500 is client-oriented, it only supports level-1 RAISE, which uses one NAND die for protection against single page/block failures (in small capacity drives fractional RAISE can be used as it requires less than a full die). The SF3700 has full RAISE support and can operate in either level 1 or 2 mode with level-2 protecting against a full die failure (the 9th channel is there for that reason). 

SandForce’s focus in the SF3000 series has been mixed performance from day one. While most modern drives boast excellent peak read and write performance, nearly every drive experiences notable loss in performance under mixed read/write workloads. We’ve been testing mixed performance as a part of our 2015 Client SSD Suite and I certainly agree with SandForce that it’s an area where improvement is needed, which is what the SF3000 series is promised to do. Seagate’s/SandForce’s internal tests put the SF3700 at much higher performance efficiency than the competing NVMe drive that Seagate couldn’t officially disclose (hint: the manufacturer starts with an I). 

Gallery: Seagate SandForce SF3000 Series SSD Controllers at Computex 2015

All in all, Seagate seems to be making progress with the SF3000 series. It’s inevitably late from the original launch schedule, but on the other hand there are only a handful of client PCIe drives on the market right now, so if the new schedule sticks and the SF3000 is as good as Seagate is showing it to be, SandForce will definitely be back in the game. The Computex announcement was relatively high-level, but Seagate hinted that they will have a truckload of new details to share within the next two months, so we will stay tuned for more.