SanDisk is a well-known brand when it comes to flash storage devices and the company recently launched its X400 SSD in the enterprise SSD segment. This means that these SSDs are not available for the consumer to buy from a store, instead they will be offered to you indirectly via laptops. These are designed to offer the best endurance ratings currently in the market, which means the chances of the SSD (Solid state drive which are generally flash memory based) failing are very very low.
Moreover, the company is partnering with HP to develop a new kind of storage solution which will be essentially 1000 times faster than the current flash based storage technology. The company also has plans to bring its very own NVMe (Non-Volatile Memory Express is a logical device interface for accessing non-volatile storage such as a SSD media via PCI Express) based SSD to the market before the end of this year. We spoke about all this and more with Mr. Vivek Tyagi, who heads the Business Development, Channel and OEM (Original Equipment Manufacturer) sales at SanDisk India. Here’s what he had to say.
With the X400, you have achieved almost double the TBW (Terabytes written) ratings of the industry standards, how is that being achieved? (The X400 is able to achieve 320 TBW instead of the average 160-170 TBW)
First of all, the total terabyte return flash is consumable, which means you can preserve its life over a period of time. Every flash memory that you use has a basic endurance or how many times you can write or use the flash. We are among the very few four companies in the world that makes its own flash memory semiconductor chips. Many other companies that sell SSDs in the market are buying flash from one of these four big companies which includes, SanDisk, Samsung, Toshiba and Micron.
So, the basic difference is that we have NAND Flash, we have our own FAP (Flash ageing prevention technique), and we make our own NAND flash. Now the second thing is, since we have our own flash we have our own controller and our own intelligent firmware with which we can manage the terabyte returns or the endurance of the flash. A number of things go into this, one is every flash when you write and erase data into it throws some error. So, in this X400 class of SSDs we use the latest error correction algorithm which is called LDPC (Low-density parity check). It is a well-documented and patented algorithm in the web, and you can see the details on LDPC. LDPC is used as an error correction mechanism to enhance the capabilities of these drives in terms of the endurance. It also has other innovative features in the firmware which enhances the TBW of the flash.
The general performance of the X400 is equivalent to the Z400s, is there an upper speed cap which can’t be struck down?
It is not an upper cap, technology wise. There are different grades of flash. SLC (Single-level cell) is pretty much very old and obsolete and MLC flash which is two bit for cell, and now there is three bit per cell which is known as TLC flash. Z400s is MLC (Multi-level cell) based. What we use in X400 is TLC with 1G Node, now with that grade of flash, to make an SSD and sell to an OEM or to the consumer, there is also price sensitivity involved.
SSD, with all due respect to its performance, is still far more expensive than a hard disk drive. So, if we make further, faster rides and leads into it by using MLC, which is a more sophisticated algorithm and controller, then on the price side we start to have challenges. So, there are no technological barriers on these fields but these are the sweet spots that are good enough for a laptop or consumer grade device. We could have a faster flash, we could have some other versions of SSD for enterprise which are faster but then we use a different grade of flash at a different price.
So as I see, X400 is available in both M.2 format as well as 2.5-inch SSD enclosures, why has the mSATA platform not been included?
mSATA is available in Z400s. That format is used in embedded applications, so if you’re doing digital signage, video surveillance, other applications and non-computing applications of SSD. For example, ATM machines that also use hard disk drives could be replaced with SSDs, so mSATA (data interface used generally by 1.8-inch SATA drives) used in a variety of embedded applications and in those applications the capacity required are relatively smaller. So, Z400s is targeted at many of those embedded applications that include digital signage, point of sales terminal, ATM machines etc.
When you look at X400, the main target is the laptops and other mobile machines but capacities are much higher. It starts and goes all the way to 1 terabyte capacity. So because of that in the laptop and mainstream PC segments these are the most preferred 2-and-a-half-inch for hard disk drive replacements and M.2 for certain OEM class applications.
While the X400 is an enterprise class SSD, do you have plans to make it available for end users right off the shelf?
The answer is absolutely yes. So, since I don’t handle retail I won’t be able to comment on whether it will be available in every store or online. But, if you look at the end user in terms of cloud data centre service providers or other companies that buy enterprise SSDs, we do have distributors in India who stopped these SSDs and we are already supplying enterprise class SSDs to many data centre customers in India. That is a direct B2B business so you won’t see it in stores or online but we are supplying enterprise class SATA and SAS SSDs (serial-attached SCSI solid state drives which are generally used in place of an HDD) to end users. We will be pushing it now, starting next quarter, but the enterprise grade is already being sold in India.
In October 2015, SanDisk announced its partnership with HP on a new kind of faster storage which is expected to be 1000X faster than the current flash based storage system, is this something similar to the 3D XPoint technology?
In terms of initiative and objective, it is similar for sure, but what companies are trying to create is a storage class memory which is not volatile. Now let me take you from a laptop to a server environment. In the server, you basically have different memory hierarchies, so at the heart of the server you have the X86 processor, which has its own level 1 and level 2 cache memory that is built into the chip. Outside that, you have a memory which is called DRAM, or Dynamic Random Access Memory. DRAM is extremely fast, the latency is only 100 nanoseconds but DRAM has 20 times more power consumption than flash, and it is 20 times more expensive than flash.
Now DRAM is also a volatile memory so when you remove the power, whatever you write in the DRAM, is lost. Now, the flash is a non-volatile memory which means it retains its flash even when there is no power. While flash is 1000 times faster than HDD, it’s not as fast as DRAM, so the companies have been trying to develop a memory, known as storage class memory that could eventually replace these two. So it’s just as fast as DRAM and its non-volatile like flash.
Today the industry is not yet there, whatever you’re hearing in industry announcements from us are steps in that direction to come out with a new type of memory that is today sitting somewhere between flash and DRAM . Now with HP, those products are more targeted in the 2017-time frame. 3D X400 is not a replacement for flash, it’s targeted at a different type of application.
What is the technology that SanDisk is working on?
DRAM is another storage class memory that we are trying to develop, not using NAND flash, it will be a different type of memory. The ghost of it is to be able to replace flash in terms of density, price, and non-volatile characteristics of flash, and try to come close to DRAM performance.
Adding to the previous question, while Intel has revealed plans to bring out its commercial grade SSDs based on its 3D XPoint technology by the end of the year, can you give me a time frame as to whether this product, whatever it is, will be coming to the commercial market in India?
It is slated for 2017, I don’t have the timelines for you, but I can definitely tell you that they will be targeted towards the enterprise market.
With the competition growing, will we see a very drastic price drop in the flash based storage market?
Price is a function of multiple things but mostly it’s from the competition, if your competition drops their price, you are forced to drop your price as well. The second thing is a major drop in price really comes when the industry makes a technology transition.What I really mean when I say a technology transition in NAND flash is the movement towards 3D NAND. Only when the industry enters into 3D NAND will we have the advantage of the high capacity that drops the price in 3D NAND. I think in 2017 or 2018 you will see a steep decline in consumer SSD pricing, when there is a steep decline in price, that’s when you’ll see the market really take off in a big way, replacing HDDs and laptops and gaming machines.
Will we see SSD prices coming down to HDD prices?
Not exactly at par, but at striking range. With the benefits of SSD, people will be much more willing to make the replacement. Today prices have come down but they are still 4 times or 5 times the HDD price. So that major transition will come in 2017.
Since, you have already acquired Fusion-Fo, will we see a NVMe Drive from you later this year?
We already supply in India and to all the leading companies around the world. Let’s say you install a PCIe card into Windows or a machine that’s NVMe compatible, then the driver is already part of the package. Today you get an automatic driver and it starts working. With PCIe, which we acquired with Fusion-io, the only thing we have to do is download the drive, the NVMe is gone. Because drivers are so highly optimized, the performance on a PCIe card especially when you write the data, is far better than any other PCIe SSD in the market. We are working on NVMe compatible SSD as well to have it be ready by year end. But for the enterprise market, we already have a PCIe flash SSD and the performance is superior to anything in the market.
So, the only difference when NVMe version comes is the standard out of the box driver, with our PCIe you just have to install the driver but the performance is better.
My last question would be, what are the other enhancements we can see in consumer grade SSDs in the future?
So, most of the enhancements will come from the interface. Today it is SATA, so even in the client SSD we are still going to PCIe interface in the future.
Today the only laptops with PCIe is Apple and Macintosh, but I think most users in this space will soon have it. So interface and the speed is one area, the other area is with the migration towards 3D NAND which will help in the capacity going up and the dollar per gigabyte coming down, so I think a few years down the line, you will see these few changes happening.