OCZ RevoDrive 3 X2 PCIe SSD Performance Preview

The RevoDrive 3 X2 and VCA 2.0

The RevoDrive 3 X2 employs an entirely new processor and controller architecture.  The first generation of RevoDrive products made use of Sandforce SF-1200 series Flash controllers and now the RevoDrive 3 is taking advantage of SandForce's latest SF-2200 series controller, with four SF-2281 chips per RevoDrive 3 X2 design, two on each of the card's dual PCBs.  These SandForce controllers are 6Gbps SATA capable with a max sequential read/write speed of 500MB/s respectively and a max throughput of 60K IOPS with 4K transactions.  These are the same SSD controllers you can find on OCZ's Vertex 3 series drives, along with Micron NAND Flash.

These four controllers, two on the daughter card, all connect serially to a main RAID processor on the base board and that's pretty much where the real magic happens.  Figuratively at least, because OCZ is holding details of the main RAID processor technology very close to the vest.


Where we scoffed a bit at the previous generation RevoDrive's implementation of a PCI-X to PCIe bridge, bolted up to a Silicon Image PCI-X RAID controller, the RevoDrive 3's design is dramatically more elegant, with fewer chips to get the job done and native PCI Express links on the back-end to talk over the edge connector of the card.


The "magic" we spoke of earlier happens in OCZ's ICT-0183 chip that you can clearly see in the shot above (right).  This is what OCZ is calling their "SuperScale Storage Accelerator."   If you follow the traces to and from the chip, you'll note very neat and clean serial pairs from the SandForce controllers (SATA links) and on the back side of the chip there are four more pairs running down to the edge connector; these are PCI Express links -- a X4 Gen 2 connection to be specific.  Easy right?  Not so fast.  There's a lot that's going on under the hood of OCZ's ICT-0183 SuperScale processor.  Though OCZ would not confirm this, we believe the ICT-0183 is actually based on Indilinx intellectual property and technology that OCZ picked up when they acquired the company back in March of this year. OCZ now also has a large team of 80+ software engineers at their disposal with the Indilinx acquisition.

We're told OCZ's new SuperScale storage processor is a combination of ARM cores, SATA and PCI Express interfaces and of course a bit of bridging in between them.  OCZ didn't give us specifics of the processing engines within the SuperScale Accelerator, but they did give us a high-level functional block diagram that shows what's going on with the RevoDrive 3 X2's design implementation.

OCZ's SuperScale Storage Accelerator (left) with VCA 2.0 - System Topology

So what we're looking at here is OCZ's Virtualized Controller Architecture (VCA), as it is implemented in the RevoDrive 3 X2.  OCZ's SuperScale processor is the square block on the left, where command queuing and load balancing takes place.  As it turns out, the SuperScale Accelerator is much more than just a simple RAID controller and SATA to PCIe bridge.  It also supports what OCZ is a calling "Complex Command Queuing Structure" or CCQS.  CCQS is a combination of Tagged Command Queuing (TCQ) and Native Command Queuing (NCQ) and along with what OCZ calls their "QBA" or Queue Balancing Algorithm, performance is optimized and workloads are balanced across the drive's RAID stripe with all controllers on the board.  OCZ can also bring out up to two SuperScale processors per PCI Express slot/card.  However, RAIDing a pair of RevoDrive 3 X2s cards together, though possible, is not recommended.  OCZ notes that their upcoming Z-Drive R4, the enterprise class version of the RevoDrive so to speak, will officially support this.

Finally, as we mentioned, OCZ is talking up their VCA technology again with the RevoDrive 3 X2 and they're claiming that this is the second generation of their Virtualized Controller Architecture, that was briefly and quietly introduced a few months back with the Z-Drive R3.  Yes, we missed the first iteration too but hey, who's counting, and we'll assume 2.0 is better than the first gen.  The Z-Drive R3 didn't make it to market in any great quantity, so it will be interesting to see how VCA 2.0 takes off with the RevoDrive 3 X2 and the upcoming Z-Drive R4. 

Regardless, OCZ's also claims the SuperScale Processor on board the RevoDrive 3 X2, supports the VCA 2.0 architecture and offers the following benefits natively.
  • TRIM Command and SCSI Unmap for thin provisioning and reduced overhead with garbage collection for performance maintenance.
  • Consolidated SMART monitoring of devices in the VCA (Virtualized Controller Architecture).
  • User-selectable Data Recovery or Non-Stop modes in the event of drive failure.
  • Power fail protection with on-board non-volatile memory for delayed transactions during power loss or system standby.
So let's sum this up for you.  Basically, the RevoDrive 3 X2, though essentially a RAID architecture, supports just about any modern drive technology for maintenance and health monitoring, including TRIM and SMART.  Also, we should note that since our card is an early prototype, we were not able to prove out that the product supports power standby mode, since early boards have errata preventing it from functioning properly.  We are assured by OCZ that retail product will support system standby and sleep.  But we digress... What do you say we stop messing with the particulars and just fire this thing up?

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