FMS 2014: Silicon Motion Showcases SM2256 SSD Controller with TLC NAND Support

A couple of weeks ago at Flash Memory Summit, Silicon Motion launched their next generation SATA 6Gbps SSD controller. Dubbed simply as SM2256, the new controller is the first merchant controller solution (hardware + firmware) to support TLC NAND out of the box and succeeds the SM2246 controller we tested a while ago with ADATA’s Premier SP610. The SM2246 was not the fastest solution in the market but it provided decent performance at an alluring price and the SM2256 is set to lower the total cost even more thanks to support for lower cost TLC NAND.

The SM2256 continues to be a 4-channel design and I am guessing it is also based on the same single-core ARC design with most changes being in the ECC engine. NAND support includes all NAND that is currently available including Toshiba’s 15nm TLC NAND and the controller is designed to support 3D NAND as well. DDR3 and DDR3L are supported for cache and the controller is also TCG Opal 1.0 compliant. 

To make TLC durable enough, the SM2256 features Low Density Parity Check (LDPC) error-correction, which is a new ECC scheme that is set to replace BCH ECC. Intel did a very detailed presentation on LDPC at FMS a few years ago, although I must warn you that it is also very technical with lots of math involved. Silicon Motion calls its implementation NANDXtend and it has three steps: LDPC hard decode, soft decode and RAID data recovery. Basically, hard decode is much faster than soft decode because there is less computation involved and in case the ECC engine fails to correct a bit, the RAID data recover kicks in and the data is recovered from parity. Silicon Motion claims that its NANDXtend technology can triple the endurance of TLC NAND, making it good for ~1,500-3000 P/E cycles depending on the quality of the NAND. Marvell’s upcoming 88SS1074 controller supports LDPC as well and I will be taking a deeper look at the technology once we have a sample in our hands. 

TLC is expected to become the dominant NAND type in four years, so focusing on it makes perfect sense. Once the industry moves to 3D NAND, I truly expect TLC NAND to be the NAND for mainstream SSDs because the endurance should be close to 2D MLC NAND, which eliminates the biggest problem that TLC technology currently has.

The SM2256 is currently in customer evaluation and is expected to enter mass production in Q4’14 with shipping devices coming in late 2014 or early 2015. 

SanDisk Releases Ultra II SSD: Bringing More TLC NAND to the Market

It is a busy day in the client SSD space as earlier today AMD announced the company’s first SSD, the R7, and now SanDisk is releasing the Ultra II to the mainstream market. The Ultra II is based on SanDisk’s second generation 19nm TLC NAND, which means that the Ultra II is the first non-Samsung SSD to ship with TLC NAND. We have covered TLC NAND several times already, but in short TLC NAND provides lower cost at the cost of performance and endurance, making it a feasible option for value drives.

Similar to SanDisk’s other client drives, the Ultra II is based on the Marvell 88SS9187 platform. SanDisk’s expertise lies in the firmware development and NAND know-how, which has generally given them an advantage over other Marvell based solutions. 

Unfortunately I do not have the full spec sheet yet, so I have to go by the limited details listed in the press release, but I will be updating the table with more specs as soon as I get them. Update: Full specs added.

The Ultra II utilizes SanDisk’s nCache 2.0 technology, which operates a portion of the NAND in SLC mode to increase performance and improve reliability. As a result, the Ultra II is able to achieve write speeds of up to 500MB/s even at the lowest capacity, although it should be kept in mind that this is peak performance — as soon as the SLC buffer is full write speeds will drop quite dramatically. 

SanDisk is also bringing a new version of its SSD Dashboard along with the Ultra II. The new version features support for 17 difference languages and includes “Live Chat” in case the user has any questions about the Dashboard or SSD. Additionally, SanDisk is including cloning and antivirus features via third party software (Apricorn’s EZ GIG IV for cloning, Trend Micro Titanium Antivirus+ for malware) with the goal of helping users to transition from a hard drive to an SSD. Combining antivirus with the SSD Dashboard might seem a bit odd but it actually makes sense. When you are about to clone your Windows install to a new SSD, the first thing you should do is a run an antivirus scan to make sure that no malware will be transferred through cloning because malware can ruin the faster user experience that an SSD provides.

Samsung certainly set the bar high with the SSD 840 and 840 EVO, so it will be interesting to see how SanDisk can match that. Pricing is very competitive with the 840 EVO and Crucial MX100, so as long as SanDisk has been able master the firmware for TLC the Ultra II should a viable option for value oriented consumers. The Ultra II will be available next month and we are scheduled to get review samples within the next couple of weeks, so stay tuned for the full review!

AMD Jumps Into the SSD Market: Radeon R7 Series SSD Launched

Back in 2011, AMD made a rather unexpected move and expanded its Radeon brand to include memory in addition to graphics cards. With today’s announcement AMD is adding another member to its Radeon family by releasing Radeon R7 Series SSDs. Similar to AMD memory, AMD is not actually designing or manufacturing the SSDs as the product design and manufacturing is handled by OCZ. In fact, all the customer support is also handled by OCZ, so aside from the AMD logo AMD is not really involved in the product.

Partnering with OCZ makes sense because OCZ’s focus with the Barefoot 3 platform has always been gamers and enthusiasts and that is the target group for AMD’s R7 SSDs as well. OCZ is a now owned by Toshiba, so OCZ has direct access to NAND with guaranteed supply, whereas fabless OEMs (e.g. Kingston) could face supply issues that might harm AMD. Here’s the quick overview, which of course will be essentially the same as certain existing Barefoot 3 products.

The R7 is based on OCZ’s own Barefoot 3 controller and it is the same higher clocked M00 version (397MHz) as in the Vector 150. The new ARC 100 and Vertex 460 use the M10 version, which runs at 352MHz instead of 397MHz but is otherwise the same silicon. Performance wise the R7 SSD is very close to Vector 150 with slightly lower random write performance, although random read performance is marginally better in turn.

The biggest difference between the two is endurance as the Vector 150 is rated at 50GB per day for five years (91TB total) while the R7 is rated at 30GB per day for four years (43TB total). The firmware in the R7 is tailored for AMD, although I was told that the customizations are mainly wear-leveling related to increase endurance over the Vertex 460, so there should not be any surprises in performance. The NAND is also different as the R7 utilizes Toshiba’s A19nm MLC, but OCZ should be making the switch to A19nm across its whole client SSD lineup soon to cut costs. 

The motivation behind AMD’s move is identical to the reason AMD entered the memory market. AMD wants to provide users an “AMD-only” experience by offering as many of the components as possible. Another argument AMD had is that providing more AMD branded products makes it easier for novice PC builders to pick the parts because the buyer does not have to go through the trouble of deciding between dozens of products and making sure the parts are compatible with each other. In addition to providing an easier purchase experience, AMD can also use the R7 SSDs in bundles and promotions, which is definitely more lucrative than using third party components. 

Of course, the ultimate reason behind the move is that SSDs are becoming a mainstream product, and they provide another revenue source for AMD. AMD has not been doing that great financially lately and having an extra low risk revenue source is definitely welcome, even though client SSDs are not exactly a high profit market anymore. Then again, AMD is not investing much into SSDs since development and manufacturing is done by OCZ, so even if Radeon R7 SSD sales end up being low, AMD has no long-term investment to protect. The announced pricing is generally in line with what we’re seeing for the existing OCZ Vector 150 products, though mail-in rebates can actually drop the Vector 150 below Radeon R7 SSD levels.

All in all, the R7 will not provide much from a technological standpoint since it uses the same platform we have tested several times, but it will be interesting to see how AMD bundles the R7 with other AMD products. AMD now has an opportunity to provide even more extensive bundles (CPU/APU, GPU, RAM and SSD); all that’s left is for AMD to begin offering Radeon branded motherboards, power supplies, and cases to provide the ultimate AMD-only experience. Whether that happens remains to be seen, but AMD is trying an aggressive bundling strategy to increase their desktop CPU sales.

We have samples of the Radeon R7 SSD on the way, so stay tuned for the full review!