The SSD Flash – June 2010

James E. Bagley, senior analyst
Deni Connor, principal analyst

June 2010 brought many new facets to the solid state drive market. The release of Apple’s iPAD, along with booming sales of the iPhone4 has put some predicted stress on the NAND Flash memory supply. According to component follower DRAMeXchange, in order to fulfill the demand for these Flash-based products, up to 20% of worldwide chip fabrication will be going into Apple products. This is a healthy trend, as many enterprise products have been made possible by successful consumer products. A good example is the laser bar code reader, which was made possible by cheap lasers developed for CD and DVD players. The Flash memory demand will encourage more foundry capacity and investment in the smaller geometries necessary to drive the cost per gigabyte steadily downward.

WhipTail Tech releases SSD SAN appliance for VDI
Virtual desktop infrastructure promises tremendous advantages for organizations that require a large number of workstations. Universities, hospitals, financial and insurance institutions have all examined the benefits of lowered capital expenditure and operating expenses associated with ultra-thin clients. But there is a big problem: the performance of storage systems in the virtual desktop environment nosedives to unacceptable levels after a relatively small number of clients are deployed. WhipTail has been building an all solid state drive (SSD) storage area network (SAN) appliance since 2008 and has focused recent performance improvements around optimization for the virtual desktop environment.

We recently spoke with James Candeleria, WhipTail’s CTO, who pointed out two important data points regarding virtual desktops. First, each thin client demands from 20 to 40 input-outputs per second (IOPs). The fastest hard disk drive (HDD) tops out at below 200 IOPs. As a result, each drive can only handle ten or fewer users. Organizations looking to support thousands of thin clients immediately run into a brick wall in terms of storage costs. The second important data point is that each thin client requires from 1GB to 2GB for the virtual image. This creates an ideal application for the WhipTail 2U SSD appliance that can support up to 6TB of data and yields 150,000 IOPs. Based on these metrics, the Whiptail Racerunner Virtual Desktop XLR8r appliance can support upwards of 7,500 thin clients. The virtualized images can be retained in SSD and HDDs can handle the rest of the database applications. In addition to saving money on the number of HDDs needed to support the systems, the power requirement of the appliance, at 180 watts, is a tiny fraction of that of a large HDD array.

Adaptec expands its MaxIQ SSD caching, sells unit to PMC-Sierra
With a major expansion to its ground-breaking MaxIQ Solid State Drive (SSD) caching product line, Adaptec has released three new PCIe storage controllers and software that supports a wide variety of SSDs and provides enterprise management features. Targeted at enterprise data centers that need higher performing storage directly attached to servers, the new MaxIQ products allow customers to configure open, high performance hybrid arrays. The storage controllers support 3Gbit/sec. Serial Attached SCSI (SAS) and Serial ATA Hard Disk Drives (HDD) and tape drives, as well as SSDs from Intel, OCZ, STEC and Samsung. Adaptec storage management software can be used to monitor and configure the performance of the controllers, and can provide analytics to determine the optimal mix of SSD and HDD. An HDD can be configured to mirror an SSD for data protection while forcing all reads to the SSD.

The original MaxIQ kit consisted of a software load for any Adaptec 5x or 2x RAID controller and a 32GB Intel X25-E SSD. This kit has been enhanced to support the 64GB X25-E and has performance enhancements in the 60% range.

In related news, silicon manufacturer PMC-Sierra acquired Adaptec’s RAID and solid state drive business for $34 million cash. Adaptec will retain its Aristos ASIC technology business, certain real estate assets, more than 200 patents and approximately $400 million in cash and marketable securities. The Adaptec RAID and SSD adapter team will move to PMC-Sierra.

PMC-Sierra subsequently announced a new 6Gbit/sec. SAS controller module, which will no doubt be carried into future products. The BR5225-80 RAID adapter uses PMC-Sierra’s multi-core SRC 8×6G RAID-on-Chip controller and software and connects the PCIe 2.0 bus to eight SAS/SATA ports at up to 6Gbit/sec. It delivers 136,000 IOPS in a RAID controller and can achieve as many as 300,000 IOPS using 6Gbit/sec. SAS technology. The PMC-Sierra maxRAID BR5225-80 adapter is sampling to OEM customers and lists at a price of $495.

Seagate fires first round in the modern hybrid drive wars
With all of the advancements in Flash memory technology and hot data caching algorithms, it was only a matter of time until a major hard disk drive (HDD) manufacturer brought a drive to market that incorporates the best of both worlds. Seagate has announced shipments of its Momentus XT hybrid drive that combines rotating media at 7200 RPM with 4GB of single level cell (SLC) Flash memory. Seagate’s Adaptive Memory technology analyzes frequently read data areas and copies these blocks to Flash acting as purely a read cache. Over time, and depending on the usage patterns, this type of algorithm has been proven in hybrid arrays supplied by many high end products, including big dollar 3PAR storage networks. What hasn’t been available is hybrid technology in a 250GB drive that costs $115.

Single-bay laptops are the perfect application for a hybrid drive. Hot data can be accessed without spinning up the hard drive, saving on battery capacity and providing instant access to most users’ data that is read frequently. And in drive capacities of 250GB, 320GB and 500GB, there is plenty of room to store the big files, like pictures, music and movies that many people love to carry around on their laptops. These big files, under the adaptive memory caching algorithm, will stay on the hard drive. But metadata, boot blocks, frequently used applications and indices will automatically stick in the Flash memory. Couple rapid boots and application startup with longer run time between battery recharge cycles, spending $160 on a 500GB drive in your laptop could be Nirvana for many users. For me, I still haven’t used more than 50GB of my 250GB drive (I do run disk cleanup about once a month) and the keys will fall off my keyboard before I fill the drive. But then, I watch movies on my big HDTV and don’t consider MPP music as part of my net-worth. In any event, this is a drive I would gladly fork out the $115 to get.

Interestingly, Seagate opted for the more expensive SLC Flash memory for this low cost drive. To me, this seems a prudent approach. SLC has faster access and better longevity than multi-level cell (MLC) Flash, which stuffs two or more bits into each physical area (cell). In the many analyses of hybrid storage arrays, the ratio of solid state memory to HDD can be very small and still reap performance gains of more than an order of magnitude. At 4GB for 250GB to 500GB, this strikes me as a little low, but the first product reviews that analyze laptop workloads indicate that it is sufficient for dramatic performance increases. Using a single 4GB module, cost factors do not multiply like pure solid state drives (SSD) that need dozens of modules to achieve a 250GB capacity. In another conservative design decision, Seagate opted for a 3Gb Serial ATA interface, as opposed to the latest 6Gb chips. Since the laptop market is targeted, few could take advantage of a 6Gb design anyway. Anand Shimpi has done a quick review of the Momentus XT and while I agree with him that a larger Flash memory will improve performance, it will be at an additional cost at a rate of about $4 per GB. Just to go to 8GB, a $115 drive becomes $130, and now people start looking back to $75 drives in the trade-off. Anand’s review can be found at: http://www.anandtech.com/show/3734/seagates-momentus-xt-review-finally-a-good-hybrid-hd

OCZ first to market with enterprise-class SSDs using the SF-1500 controller
Last month SandForce announced its SF-1500 controller firmware was shipping in its MP or Mass Production release. Thursday, OCZ unveiled the Vertex 2 Pro and Vertex 2 EX SSDs based on the SF-1500.
While identical at a hardware level to the SF-1200 consumer controller, the SF-1500 differs substantially in its firmware, features, and test requirements. The SF-1500 also has a super capacitor to keep the circuit alive so the controller’s internal buffer can be written to the Flash memory if a power failure occurs. Both the Vertex 2 Pro and Vertex 2 EX have this feature.

The Vertex 2 Pro is based on 34nm 2-bit per cell Multi-Level Cell (MLC) FLASH, while the Vertex 2 EX uses 34nm Single Level Cell (SLC) that will endure about ten times the program/erase cycles of the MLC and is recommended for applications that are write-intensive. The flash is currently produced at the Intel-Micron foundry, but OCZ is free to qualify and purchase anyone’s flash. Both drives come in a 2.5” format and support the Serial ATA II (SATA II) interface. Also, a Serial Attached SCSI (SAS) interface will be made available to clients using LSI SAS bridge silicon. Enhanced error correction (ECC) is used to provide more data to detect and correct errors. This flies in close formation with the AES-128 encryption which involves similar calculations as the ECC algorithm.

Transfers are rated at 285Mbit/sec. for reads and 275Mbit/sec. for writes and 4KB random writes achieve a remarkable 50,000 Input-Outputs per second (IOPs). The many reviews of the SF-1200 based products have verified the tremendous reduction of the write penalty inherent with flash, which involves special algorithms for compression and dedupe, again in close formation with the encryption processing.

As is the trend, 50GB, 100GB and 200GB versions will be available, reflecting the formatted capacities from 64GB, 128GB and 256GB raw capacity respectively. Warranty is three years. Pricing and shipment schedule was not available.

Violin Memory 3200 is game changer
Violin Memory’s new V3200, in a 3U (5 ¼” high) rack package offers scalability from 500GB to 10TB in a single appliance, and can scale to more than 140TB by adding multiple appliances in a rack. Using Single Level Cell (SLC) Flash memory technology, the 3200, in a full-up configuration, has an MSRP of about $20 per GB. This makes the 3200, which supports PCIe and 4/8Gbit/sec. Fibre Channel connectivity, price competitive with enterprise hard disk drive (HDD) systems on a cost per GB basis. Of course, we expect SLC appliances to operate at super speeds, but the architecture embodied in the 3200 supports aggregate bandwidth that trumps everything currently available.

We spoke with Matt Barletta, Violin’s vice president of product marketing who covered the details of the 3200 announcement. Matt also detailed a new record for blade servers running the TPC-E online transaction processing simulation set by HP.

Using the TPC-E online transaction processing (OLTP) benchmark for SQL servers in a simulated brokerage application, an HP Proliant BL685c G7 Blade Server recorded a of 1,464.12 at a cost per TpsE of $302.49, a new record for blade servers. The system used four V3200 appliances each with 2.6TB of capacity. Internodal connectivity was via 20Gbit/sec. Ethernet. Host connectivity used two Violin quad head 8Gbit/sec. Fibre Channel interfaces. This was the first time HP had used another vendor’s memory system in a TPC benchmark. When compared with other top ten benchmarks that used as many as 2,000 HDD spindles to achieve throughput using RAID to spread data across HDD arrays, the HP system showed maximum response times of less than three seconds, unlike other SSD and HDD systems that had response time spikes upwards of 18 to 68 seconds. What was more impressive was that the ProLiant blades were running the Violin Memory Arrays at 50% utilization, implying that other server configurations are capable of delivering almost twice the transaction rate.

Violin has established a significant strategic partnership with Toshiba, and is in a position to buy chips from the world’s largest volume flash manufacturer at attractive price points. In addition, Violin has serious intellectual property for switching between flash modules that allows aggregation of an order of magnitude over existing appliances with linear growth in bandwidth as additional memory arrays are added. One key to the price performance is the Violin Intelligent Memory Module (VIMM). Like a DIMM, only built out of Flash instead of DRAM, a memory array supports up to 84 VIMMs, each with 128GB of SLC Flash. Violin Switched Memory (VXM) technology and Violin’s Flash RAID provide the rest of the secret recipe. By aggregation and splitting the Flash control logic between the controllers on the system board and the individual VIMMs, substantial economies of scale can be achieved when compared with drive format SSDs that need to self-contain Flash control and provide drive emulation over a Serial Attached SCSI (SAS), Fibre Channel (FC), or Serial ATA (SATA) interface, all of which have individual silicon and connector hardware costs, not to mention throughput and latency penalties.

Performance, Flash management and reliability are enhanced by the patented Flash RAID implementation that uses a four VIMM plus one (like RAID 5) to spread data across multiple devices, hide erases and even allow hot swapping of VIMMs.

Connectivity support is wide and deep. For direct attached storage (DAS) configurations, PCIe support is offered with both SCSI and block-level drivers for Windows, Solaris and Linux. For SAN and LAN connectivity, network attached storage gateways from FalconStor, OpenFiler and systems running Violin software with OpenSolaris are available that provide up to ten 8Gbit/sec. FC and up to four 10Gbit/sec. Ethernet or Fibre Channel over Ethernet options. Violin’s recent acquisition of NAS filer and ‘memchached’ software developer Gear6 bodes well for future NAS file connectivity.

Violin will automatically benefit from Moore’s law as shrinking geometries reduce the cost per GB of Flash memories. In addition, with current and future connectivity options, a one-stop shop for both block and file based systems is available. The VIMM modularity and aggregation capabilities of the V3200 are unmatched, and provide an excellent distribution of Flash storage workload between the system controllers and the individual memory modules. Violin is in a unique position to benefit from the significant dollars allocated to memory systems versus individual drives. Strong relations with HP, Microsoft and other major vendors will help drive the Violin Memory Arrays into a wide variety of high-performance applications across a number of industrial and enterprise users.

OCZ’s new RevoDrive brings PCIe speed to the masses
In what is becoming an increasingly crowded market, compared with a year ago when Fusion-io practically had the space to itself, OCZ has a new, value priced PCEe four-lane SSD that achieves cost points that will allow this technology to find its way into workstations rather than just high-end servers.

When compared to enterprise products from Fusion-io, LSI and Texas Memory, the 120GB street price of $370 for a 120GD drive and $700 for a 240GB drive, the pricing represents a dramatic decrease in cost when compared to the enterprise PCIe drives that go for ten to twenty times that amount.

OCZ achieves this cost point in a very clever manner by using twin SandForce SF1200 controllers coupled with MLC and uses a Silicon Image SiI3124 PCI-X to 4 port 3Gbit/sec. SATA controller. The controller supports up to four SATA devices, but only two are used in the current package. Future products could add two more SF1200 controllers and boost performance beyond the already hot 540 MB/sec. reads and random 4K writes at 75,000 IOPs. The SATA controller provides standard driver support across all operating systems and relieves the system CPU of performing the drive control and flash management functions. The OCZ RevoDrive is available now from all of the usual aftermarket suppliers.

Dell EqualLogic provides automatic storage tiering
The new Dell EqualLogic PS6000XVS/PS6010XVS systems provide automatic SSD storage tiering with the
Firmware 5.0 release. The system is targeted at virtual desktop workloads, which is becoming a recurring theme.