Interestingly, our 100GB Vertex 2 Pro sample actually carried 128GB worth of flash memory. This is because the Vertex 2 Pro not only loses the ~7% from the GB to GiB conversion, but SandForce also specifies an additional 20% flash be set aside for spare area. SandForce uses this reserved space for its DuraWrite technology, which is designed to reduce write amplification and extend endurance. Once formatted the drive only has 93.1GB of usable space. SandForce claims this loss is unavoidable and that this method will eventually have to be adopted by all future SSD drives. Obviously, the lost capacity increases as the drives become larger. The 400GB model which has 512GB of flash memory on the PCB only has 372.5GB of usable storage space. Something else we found interesting about the Vertex 2 Pro and the SandForce SF-1500 controller is that there is no DRAM cache. SandForce is able to do away with the cache by writing less to the flash, meaning that there is less data to account for and smaller tables to manage on the fly. Because less data is being written to the flash SandForce claims that SSD manufacturers can use cheaper memory to save on costs. The SF-1500 carries a small cache inside the controller which is thought to be a few megabytes in size, though the exact figure has not been disclosed. Inside the controller there’s also the Tensilica DC_570T CPU core, this is used in both the SF-1200 and SF-1500 models. When we questioned the use of the CPU core, SandForce said it has little to do with the performance of the controller and stated that it is everything else around the CPU that matters. The OCZ Vertex 2 Pro features Micron 29F64G08CFABA flash memory. In total there are 16 chips (8GB each). OCZ claims maximum read/write performance of 280/270 MB/s, which translates in 12% greater read performance than the original Vertex drive, while the write performance is claimed to be an incredible 56% faster. The Vertex 2 Pro uses a slim 2.5" design, measuring 99.8 x 69.63 x 9.3mm and weighing in well under 100 grams. They are said to use 2 watts of power when in use and just 0.5 watts in standby. The Vertex 2 Pro SSDs can work in RAID if you choose to purchase more than one and they are backed by a 3-year warranty.
