|OCZ RevoDrive PCI-Express SandForce SSD|
|Reviews - Featured Reviews: Storage|
|Written by Olin Coles|
|Wednesday, 22 September 2010|
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Closer Look: OCZ RevoDrive PCI-E SSD
For this article Benchmark Reviews is testing the OCZ RevoDrive SSD, which is expected to reach speeds of 540 MB/s for sequential reads and 480 MB/s sequential writes. The 120GB Revo OCZSSDPX-1RVD0120 kit is built using dual SandForce SF-1222 controllers with 7% over-provisioning, which means that 120GB out of 128GB NAND flash contained in this SSD are allocated for data use. The OCZ Revo PCI-E SSD comes in 50/80/120/180/240/360/480GB capacities, and all models receive OCZ's three-year warranty.
Most modern motherboards with PCI-Express 2.0 slots will support Revo as a boot device, such as Intel's 5x series and AMD's 8xx series, but older motherboards may require a BIOS update. OCZ offers a list of compatible motherboards on their product website.
SSDs are catching on quickly because they work equally well in PC, Linux, or Apple Mac computers, but the RevoDrive is different. Instead of packaging the NAND and drive controller into a SATA-connected enclosure, OCZ has built the Revo to utilize a single 4x PCI-Express 1.1 slot. Because it requires a 4x PCI-Express 1.1 slot to operate, the OCZ RevoDrive SSD is best suited for enthusiast-level desktop computer systems or performance-orientated application servers where 75,000 IOPS could really make an impact. SandForce SF-1200 series SSD controllers have been designed with a focus on high-performance operational and data transfer speeds, and include encrypted data protection and improved NAND wear-leveling through their proprietary DuraWrite technology.
While PCIe effectively rules out attention from notebook consumers, it opens up a market to users in need of Hot-Plug drive support. Additionally, OCZ's PCB-0052-X02 printed circuit board allows for modular component placement, which could one day expand the platform to offer up to four storage controllers with more complex drive schemes with even faster data processing. An add-on board could be connected, which would house supplemental NAND flash and two additional storage controllers.
OCZ utilizes a Pericom PI7C9X130 PCIe-to-PCIx reversible bridge chip on their Revo SSD, which connects one x4 PCI-Express port to one standard 64-bit /133 MHz PCIx port. The Pericom PI7C9X130 bridge features a 10KB buffer: 4KB for upstream reads with 2KB for upstream writes, and 2KB for downstream reads with another 2KB for downstream writes. From the PCI-Express bus, data travels through the Pericom PI7C9X130 located on the printed circuit board (PCB) directly above the gold-fingers into a Sil3124 RAID controller chip by Silicon Image (covered with a R sticker).
Silicon Image defines their SiI3124 chip as a PCI-Express to SATA-3GB/s controller capable of driving four ports. The current version of OCZ's Revo SSD incorporates the Sil3124 chip to drive two of the four available channels, using two SandForce SF-1200 controllers combined into a RAID-0 array to produce peak performance before reaching a collection of NAND flash components. A more detailed explanation of architecture is given in the next section...