SSD Testing Hint
Don't rely on your motherboard's SATA controller. Get a quality (And relatively cheap) LSI SASII (compatible with SATAIII / 6Gbit) HBA (Not a RAID controller, there's too much black box magic on those.) The LSI SAS 9211-4i is a lovely 4 port card that will eliminate any questions as to whether your motherboard SATA controller disagrees with a given drive.
It's also been reasonable well documented that the top-end performance of a 6gbit drive on a 3gbit controller has little relation to what you'll see on a 6gbit controller. And by 'documented' I mean either I read it somewhere on the Internet, or I did it myself... probably the former, since this sounds like a lot of work that I'd remember complaining about. Anyway it's down to latency and queue depth and things that all get better on the newer interfaces..
Also (haven't had my coffee yet, so apologies if I missed this) it doesn't seem that you specify what kind of data you're writing to the drive. Sandforce controllers have lots of magic going on, so if you use repeating test patterns, or compressible test patterns, you'll see vastly different performance than if you have a utility which uses non-compressible, unique test patterns. I strongly suspect that many Sandforce vendors quote the best possible performance numbers found using the most unrealistic data possible.
Also, this drive shouldn't have any power fail protection, as the Sandforce 22xx line isn't supposed to support that feature. Can't see myself buying a drive that doesn't have a bank of capacitors on it these days, and I wouldn't recommend anyone else does either.