PCI Express may be the future for solid-state drives, and the interface has already taken root in OCZ's Z-Drive SSDs. The company has just announced a new one: the Z-Drive R4. Available in full- and half-height models, the Z4 has a PCI Express 2.0 x8 interface with 4GB/s of peak bandwidth to and from the system. You're gonna need the bandwidth, too, because the fastest Z4 is said to be capable of pushing data at nearly 3GB/s.
The Z-Drive achieves its impressive performance with the aid of multiple SandForce SSD controllers managed by a "SuperScale" storage controller of OCZ's design. Details are scarce on the controller, but it's part of version 2.0 of the company's Virtualized Controller Architecture. VCA 2.0 offers its own queuing system in addition to supporting both TRIM and the SCSI command set. Configurable redundancy options are built right in, and VCA also attempts to extend NAND longevity at the block level. Excellent endurance with 2x-nm MLC flash memory is a big selling point for the new Z-Drive, OCZ says. According to CEO Ryan Petersen, a 3.2TB Z4 is capable of withstanding 120 petabytes worth of writes. SLC versions of the drive with even greater longevity will be available, as well, although OCZ insists they're only necessary in extremely write-intensive environments.
Behind the OCZ chip, you'll find up to eight SandForce SSDs controllers tied to banks of NAND. The half-height RM84 variant of the Z4 is limited to four SSD controllers, and its performance ratings drop accordingly. As one might expect, the midget card doesn't offer as much storage capacity as its big brother, topping out at mere 1.2TB.
|Interface||PCI Express 2.0 x8||PCI Express 2.0 x8|
|Available capacities||800GB, 1.6TB, 3.2TB||300GB, 600GB, 1.2TB|
|Max sequential reads||2800MB/s||2000MB/s|
|Max sequential writes||2800MB/s||2000MB/s|
|Max random 4KB writes||410,000 IOps||250,000 IOps|
|Warranty length||Three years||Three years|
OCZ isn't pinning down pricing just yet, but it indicates that R4 drives would run $6-15/GB depending on the configuration. With the line starting at 300GB, this isn't something you'll be popping into a desktop PC. The R4 is very much designed with enterprise customers in mind, and OCZ is keen to point out that it will even churn out custom form factors for its customers. Custom orders will have to wait until the end of the year. The standard Z-Drive configs are already shipping, though.
Somewhat surprisingly for such a premium product, the Z-Drive R4's warranty runs out after just three years. That's not actually atypical. Another big name in the PCIe SSD market, Fusio-io, also covers its drives with a three-year warranty. Enterprise-class mechanical hard drives usually have five-year warranties.