With the right workload, SandForce's SF-1200 storage controller has enormous potential. All three of the SF-1200-based drives we tested offer solid sequential throughput and very fast random access times across a range of transfer sizes. The SF-1200 proved particularly adept at handling random writes with larger transfer sizes, and it absolutely crushed the field when fed IOMeter workloads that contained a mix of read and write operations. Throw in quick load times and a strong showing in our multitasking tests, and all the hype surrounding SandForce looks very much deserved.
That said, the SF-1200 isn't well optimized for all situations. As our FC-Test file creation and copy results illustrate, the controller's sequential write speed appears to be much more dependent on effective use of command queuing than other SSD architectures. Microsoft's Windows 7 AHCI drivers appear to make matters worse, as does a garbage-collection algorithm that doesn't reclaim erased flash pages as quickly as Indilinx- or Intel-based drives.
I'm encouraged that SandForce is looking into these issues, but it remains to be seen whether firmware updates can smooth them out. At the very least, I don't expect these rough edges to draw blood with most users. Moving files around in Windows 7 is still plenty quick with the SF-1200, even when running Microsoft's AHCI drivers.
I would, however, temper any expectations of improved performance with SandForce's stated desire to minimize flash writes. The company's decision opt for less aggressive garbage collection was a deliberate one, and SandForce intends to pursue even greater endurance with future products. Drive longevity is something that's all but impossible for us to measure in a timely way, but I do expect DuraWrite to allow SSDs based on the SF-1200 to consume write-erase cycles more sparingly than the competition.
SSD endurance is going to be much more important for enterprise customers and notebook users than it will be for enthusiasts looking to use a solid-state drive primarily to house their operating system and applications. The SF-1200's architecture also seems to be better suited to enterprise-class workloads than to the demanding desktop multitasking scenarios we simulated with DriveBench. You need to come up with a pretty punishing workload to see this controller live up to its potential.
The fact that not even our IOMeter workloads were able to tease out a meaningful performance difference between the firmware-capped Agility 2 and the Force F100 and Vertex 2 tells me that there's little point in spending extra on SandForce drives with higher random-write ratings. The Agility 2 is already the cheapest 100GB SandForce-based drive at $360 online. Based on current pricing and the performance parity we've observed, the Agility 2 is the one I'd recommend. Plus, OCZ gives you one more year of warranty coverage than Corsair and the promise of future firmware updates that will increase the drive's capacity to 120GB.
Until that firmware update is released to the public, I'm going to reserve final judgment on the SF-1200. The higher cost per gigabyte that results from greater overprovisioning may not matter so much to potential enterprise customers, but it's a big weakness in the increasingly competitive consumer SSD market. Destiny is still to be determined for the SF-1200, then. SandForce is definitely a contender, and it's most certainly in the mix with Indilinx and Intel.
Update 5/26/2010 Corsair has extended the warranty coverage for all its SSDs to three years. The company is now free to use SandForce's mass-production "Max IOps" firmware, as well.