OCZ RevoDrive Hybrid 1TB PCI-E SSD ReviewWed, Oct 19, 2011 - 12:00 AM
OCZ RevoDrive Hybrid – A Closer Look
At first glance, it appears OCZ took a RevoDrive and slapped a 2.5″ HDD on top. Well, that’s pretty much what they did although more elegantly than just slapping it on there.
From the top view we see the 5400 RPM HDD on top with a heatsink on the far left covering the RAID controller.
Underneath that heatsink lies the SuperScale Storage Accelerator that facilitates scalable performance by employing complex command queuing structure (CCQS) and queue balancing algorithm (QBA) technologies. The aforementioned Virtualized Controller Architecture 2.0 technology aggregates performance across a pool of Virtual Logical
Drives (LUNs) through virtualization. It allows some DMA or data
management functions, including OCZ’s command queuing and QBA, to be handled on the drive which mitigates the load placed on the host CPU. What all this jargon means is that they forgo a traditional RAID controller and rely on NAND Array virtualization, accessing the NAND in parallel. Since there’s no actual RAID controller, they are able to pass the TRIM command although currently Windows does not support it in this fashion so don’t blame OCZ.
The daughterboard on which the HDD resides, is held by four screws and does not host any of the NAND. It’s purely for the HDD mount.
In the above view, you can see how the daughterboard rests above the controller and NAND.
Looking beneath, we find the pair of SF-2281 controllers and to the left, indicated by the arrow, is the interface where the daughterboard connects to the mainboard. The SandForce SF-2281 controllers work in tandem to deliver the extreme performance on this drive. As always, they handle the mundane duties of wear-leveling, real-time compression, encryption, and error correction which is even more critical when employing 25nm NAND since errors are much more error prone than that of the NAND with the larger architecture. As always, the DuraClass technology, proprietary to SandForce, is responsible for all of the aforementioned tasks and more like TRIM and garbage collection which are supported to maintain a high level of performance for extended periods of time.
Around back, we see the remainder of the NAND flash.
Interestingly, this is the first time we’ve seen the flash modules branded with the OCZ name. We queried OCZ to see if this was third party manufactured or of their own fabrication and we were told “We now work directly with the fabs and purchase wafers instead of packaged NAND. The flash on the Hybrid is Micron 25nm Async”. So there you have it. On board is 128 GB in total comprised of 16 modules, each 8 GB in density.
Finally, if you peel back the OCZ sticker you can see that the hard drive is of Toshiba manufacture with part number HDD2K51. This is a 1TB, 5400 RPM drive in the 2.5″ form factor. Initially, we wondered why a 7200 RPM wasn’t used but the performance we saw was very good overall and having a faster HDD wouldn’t have much of an impact. The onboard cache for this platter drive is 8 MB and the average seek time is listed as 12 ms. With the hard drive in tow, OCZ reports that the the power draw for this is 8.1W idle and 10W in the active state as compared to the RevoDrive X2 at 4.3W Idle, 8.3W active.