The PQI S535 256 GB drive has 256 GB physically on board as measured in GB (1,000,000,000 bytes per GB) which is the standard unit of measure used by manufacturers to express drive capacity. In logical measure it’s 223 GiB (1,073,741,824 bytes per GiB) which is reflected in Windows via the drive properties view. Thrown in there is about 7% overprovisioning set aside for wear leveling and drive maintenance. This is more or less the level we see from this generation of consumer drives. Enterprise level drives tend to have higher levels of space set aside.
At this point there isn’t a lot new we can say about the PQI S535 256 GB drive as SF-1200 based SSDs are a dime a dozen right now. Ok, that may draw ire from those that are still waiting on buying an SSD because of the cost but we’ve done no less than ten reviews now on such drives. PQI is a little conservative in their specifications of 250 MB/s reads and writes as we saw well above that for each in the ATTO benchmark. Performance was weaker in the tests that use incompressible data which is exactly what we expect from SandForce drives as they use real-time data compression to maximize performance.
We don’t know how much PQI is asking for the S535 or where you can get one right now, but the drives were released in December 2010 and they just sent us this sample late last month. We assume these drives are available at locations that sell PQI products.
Supporting TRIM, idle garbage collection and wear-leveling algorithms that we’ve come to know and love from SandForce controllers, long term performance shouldn’t be an issue, especially if you leave 20% or more of the drive unused which shouldn’t be all that hard on a 256 GB drive. PQI does offer a 3 year warranty to cover any defects in workmanship or premature component failure. PQI also lists Mac OS 10.1 and above as compatible which is not something you see from all drives so that may be attractive to some.
Legit Bottom Line: For those who haven’t made the step up to a SATA 6Gbps board, PQI has a very capable line of SSDs with the S535 series featuring the proven SandForce SF-1222 controller. However, these are a generation behind now and there’s plenty of competition in this class to make hard choices for consumers although if they can’t find them available to by, that choice becomes a little easier.