Some interesting details have been revealed about SandForce's SF-1200 and SF-1500 SSD controllers over at AnandTech. It appears both chips share the same silicon, and that it's the SSD firmware that caps the random-write performance of the SF-1200.
Interestingly, end-users with firmware version 3.0.5 will not get the same performance as seen in reviews, because the 3.0.1 release candidate firmware used on the review samples did not have this performance cap in place. SandForce reportedly introduced the performance cap to fix a known reliability issue that could result in a dead disk.
Not all SandForce SF-1200 based SSDs will be equal though, OCZ has a closer relationship with SandForce than other firms, they've committed a lot of resource to the company, and therefore they will get access to a faster revision of the SF-1200 firmware.
Corsair is currently shipping SSDs with the 3.0.1 firmware, but the company claims it has circumvented the reliability issue by disabling the power saving feature that caused it. AnandTech has investigated this claim and testing seems to back this up as the power consumption of Corsair's Force 100GB is 1.25W during a sequential write test, while the OCZ Vertex LE 100GB uses only 0.95W.
Corsair could keep shipping the faster 3.0.1 firmware, but if users ever have to upgrade they will lose performance.
Now we get to the other problem. The performance of 3.0.1 is the same as OCZ’s exclusive SF-1200 firmware, because the firmwares are the same. However SandForce has recently released its first MP firmware: 3.0.5. This firmware, as you’d expect, caps small file random write performance on all SF-1200 drives except for the Vertex 2 in accordance with SandForce’s agreement with OCZ. The SF-1500 version of this firmware doesn’t change performance, but it does supposedly fix the reliability problems and is available for Vertex LE owners here.
Corsair is currently testing the 3.0.5 revision for its drive but hasn’t shared it with me yet. Corsair wasn’t aware that performance dropped with this revision until I called yesterday. The release notes don’t indicate anything of the sort, Corsair was kept completely in the dark on this. Why didn’t SandForce tell Corsair? Because although it drops performance, the new firmware still runs the SF-1200 at its intended spec. The chip will continue to perform as advertised, just slower than with the RC firmware and slower than OCZ’s Vertex 2.