|SandForce SF-2000 Series SSD Overview|
|Reviews - Featured Reviews: Storage|
|Written by Olin Coles|
|Thursday, 24 February 2011|
SandForce SF-2000 Series SSD Processor Overview
Less than one year ago SandForce gained control of the consumer solid state drive market with their SandForce SF-1200 SSD Processor. This technology replaced the previous generation of Barefoot SSDs designed around South Korean-based Indilinx, Inc. While popular themselves, Indilinx Barefoot MLC SSDs lacked proper NAND management and performance dramatically degraded over time. SandForce DuraClass technology paired to TRIM support in Windows 7 has helped with this concern, but it was their RAISE technology that provides RAID-like protection for single SSD computer systems paired to AES-128 automatic data encryption that put them on top. Now preparing to ship their second generation of SSD processors, Benchmark Reviews takes a look at the differences.
SandForce introduces their new second generation solid state drives to both consumer and enterprise segments, with seven different models to choose from. On the consumer (retail) side you've got models using the older SATA 3Gb/s interface as well as the latest SATA 6Gb/s interface, while all enterprise drives utilize the 3rd-generation SATA 6Gb/s interface. More than any other factor, it's the Flash Channels/Byte Lanes configuration that these separate models. SandForce's SF-2000 series of SSDs continue to feature up to 8 data channels organized into 16 Byte lanes; similar to the previous generation of SF-1222/SF-1565 series SSD controllers, but now some models are scaled down for usage scenarios not requiring massive IO activity.
SandForce second-generation SF-2200 and SF-2100 SSD processors aren't just SATA 6Gb/s on paper - they actually require the bandwidth afforded to the host interface to deliver sustained sequential read/write performance up to 500 MB/s. SandForce DuraClass Technology is still a staple part of their feature set, but now include Trusted Computing Group (TCG) Opal-compliant Self Encrypting Drives (SEDs) support with AES-256/128 and double encryption. SF-2200 and SF-2100 SSDs also utilize high-speed ONFi2 and Toggle flash interfaces in single-level (SLC) and multi-level cell (MLC) NAND flash families from all major suppliers. The last major difference is the reduced minimum over-provisioning requirement, which continues to use an integrated buffer but returns more capacity for storage assignment.
Key Changes in SF-2200/SF-2100 Client Products
Continued multi-vendor flash memory support
The SF-2200 and SF-2100 Client SSD Processors address the needs of cost-sensitive client storage markets with many inherent enterprise-class features. These devices feature the highly sought-after SandForce DuraClass Technology including RAISE and patented and patent-pending DuraWrite features to deliver the ultimate in performance, endurance, reliability, and power management. Additionally, SF-2200 and SF-2100 Client SSD Processors feature:
SandForce SSD Product Stack
Inspecting the SandForce product stack charted above, there are a few stand-out models and at least one model that doesn't quite make sense. The SandForce SF-2141 will be the 'entry-level' consumer SSD processor, utilizing a SATA-3G interface and offering only 4 channels with one byte lane apiece for standard operational loads. SF-2181 doubles the channels for intense-IO systems, but still uses a single byte lane per channel for a total of eight. The SandForce SF-2281 will likely become the sought-after SSD controller by hardware enthusiasts, since it delivers all eight channels and foregoes the enterprise byte lane scheme in favor of a consumer-orientated 1:1 ratio. High-IO consumer systems will be well suited for the flagship consumer SSD processor: SF-2282. The SandForce SD-2282 is virtually an eight-channel/sixteen lane enterprise drive with MLC NAND, and won't be produced in the same quantities as other controllers.
Taking the specification into consideration, an educated hardware enthusiast might look at the SF-2181 and SF-2281 models and wonder what makes them different. It's a fair question, because apart from the SATA-3G/6G interface the SF-2181 and SF-2281 are actually the same drive. Both feature 500 MB/s peak read and write speeds, and both offer 60K burst IOPS. The real difference will likely be determined in price, presumably, since consumers have a tendency to pay for a higher classification of product even if it yields not measurable increase in performance.
Moving towards the enterprise segment, all drives feature an 60K IO-optimized eight channel/sixteen byte lane design with extended SMART attributes. The SandForce SF-2382 is designated for industrial/military application and is not planned to be available on the retail market. SD-2382 will feature a SATA-6G interface, and is very similar to the SF-2282, but also includes support for military erase and eMLC with no over-provisioning. The SandForce SF-2582 is a 28% over-provisioned MLC SSD without 512-byte sectors, while the SF-2682 adds 512-byte sectors.
Benchmark Reviews will soon offer several tests of retail-available second-generation SandForce SSDs, just as soon as consumer samples are available.