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OCZ's Octane 512GB solid-state drive

Indilinx returns with Everest

OCZ has been at the forefront of the desktop SSD market for several years now. Despite being something of a pioneer in the industry, OCZ has been more of a remix artist than a true original; the company's consumer-oriented SSDs have long used controller and flash silicon sourced from other firms. Flash fabs are rather expensive to build, making it unlikely that OCZ will ever be able to challenge giants like Intel, Micron, and Samsung in that arena. Controller makers are considerably more affordable, however. Earlier this year, OCZ purchased one for $32 million.

Acquiring Indilinx, the brains behind the Barefoot controller in the first Vertex solid-state drive, put OCZ in a rather exclusive club. Only a handful of companies design the flash controllers and accompanying firmware that underpin modern SSDs. Precious few of those firms sell complete products based on their wares, especially when one considers only the 2.5" SATA drives typically targeted at consumers.

Now, some nine months after Indilinx joined the family, OCZ is rolling out a line of Octane SSDs based on new controller silicon dubbed Everest. With a 6Gbps Serial ATA interface, eight memory channels, AES encryption, and support for the latest NAND flash, the Everest chip ticks all the boxes you'd expect from a modern SSD controller. The more important question, however, is whether the Octane SSD can keep up with its contemporary rivals. We've tested the drive against 16 other SSDs and a stack of mechanical disks to find out.

Climbing Everest
Before getting started, we should note that there are actually two lines of Octane SSDs. Our focus today is on the standard Octane, but there's also a cheaper S2 series equipped with a 3Gbps SATA interface and slower NAND. Both Octane families use the same Everest controller, which still bears Indilinx's name.

OCZ is being tight-lipped about many of the details surrounding the controller. However, we do know that it incorporates dual ARM cores to handle processing duties. The flash interface is spread over eight memory channels and supports 16-way interleaving, while the host interface supports the latest Serial ATA standard.

The Octane's marketing materials are quick to hype nDurance, a feature that purportedly increases the endurance of the drive's flash chips by a factor of two. OCZ would reveal only that nDurance uses a hardware engine combined with "proprietary algorithms in the FTL," or flash translation layer. It seems unlikely that a twofold increase in NAND endurance could be achieved without some form of black-magic compression, so nDurance could employ similar techniques to those used in SandForce controllers. I suspect the hardware engine might be related to the controller's support for 256-bit AES encryption. If an encryption engine is present, its algorithms could be tweaked to reduce the size of incoming writes from the host.

With an eye toward mainstream desktop workloads, OCZ has optimized the Octane for queue depths of three or less. The command queue associated with the current Serial ATA spec extends to a depth of 32, making OCZ's focus look rather narrow. That said, our own DriveBench 2.0 workload, which includes two weeks of multitasking-heavy desktop usage, agrees with OCZ's approach. More than 80% of DriveBench 2.0 requests have a queue depth of three or less.

OCZ says the Octane has been tuned to perform well with both 4KB and 8KB transfer sizes. The company also claims the drive sports "innovative latency reduction technology," although it wouldn't divulge specifics on what's innovative about the approach. The Octane's read and write latencies are listed as 0.06 and 0.09 ms, respectively.

The Everest controller will work with a range of different flash types, including ONFI 2.0 and Toggle DDR 1.0 NAND at speeds up to 200 MT/s. OCZ didn't mention support for SLC memory when it announced the Everest, but it did reveal that the controller will work with TLC memory. TLC NAND packs three bits per cell, one more bit than the MLC flash commonly found in today's SSDs.

We've yet to see TLC NAND incorporated in a solid-state drive, and the Octane doesn't change that trend; the drive uses 25-nm MLC NAND chips manufactured by Intel. These synchronous chips appear to be similar to the ones that populate OCZ's Vertex 3 SSD and other synchronous SandForce drives. The asynchronous memory typically used in cheaper SandForce SSDs will also appear alongside the Everest controller in the slower Octane S2 SSDs.

Our Octane sample came with 512GB of flash spread between 16 chips. SSD makers typically send out review units with capacities in the 256GB range, making OCZ's decision to go with a nearly $900 drive seem a little odd. The performance specifications for each capacity point illustrate the likely motivation behind that move.

Capacity Max sequential Max 4KB random Price
Read Write Read Write
128GB 535MB/s 170MB/s 37,000 IOps 7,7000 IOps $200
256GB 535MB/s 270MB/s 37,000 IOps 12,000 IOps $370
512GB 535MB/s 400MB/s 37,000 IOps 16,000 IOps $880
1TB 560MB/s 400MB/s 45,000 IOps 19,500 IOps TBA

Until the 1TB version of the Octane arrives next month, the 512GB model has the fastest write speeds of the bunch—and by quite a lot. The 256GB Octane's 270MB/s peak sequential write speed is 130MB/s shy of the rate purportedly achieved by the 512GB model. There's also a 4,000-IOps delta between the two for random 4KB writes. The 128GB variant's write performance is another step down the ladder in both categories, although there's no difference between the three in the read department.

The Octane 128GB has the sort of middling performance ratings one might expect from the 64GB member of an SSD family. SSDs of that size typically use only a handful of flash chips, preventing them from exploiting all of the parallelism available in the controller. Given the Octane's performance ratings and the fact that our 512GB drive uses 32GB NAND chips, I have a sneaking suspicion the 128GB model has only four flash chips under the hood. OCZ won't be making a 64GB version of the Octane, nor does it plan to offer that capacity in the S2 line.

Apart from the terabyte model, all of the 6Gbps Octane SSDs feature 512MB of cache memory. Interestingly, this cache is split between two DRAM chips: one on each side of the circuit board. The DRAM is accessed through a single channel that's 16 bits wide. Micron provides the DDR3 chips, which can push bits as fast as 1600 MT/s.

OCZ's projected prices for the Octane look pretty reasonable; the 128GB model is set to sell for $200, which puts it right in the sweet spot. If we've learned one thing over the past year, though, it's that street prices can change on a daily basis. Octane SSDs were supposed to start shipping to retailers last week, so they should be a part of the raging solid-state price war shortly. At the moment, I only see one Octane listing online—a 256GB model at Newegg that's out of stock.

Like just about every other consumer-grade SSD on the market, the Octane is covered by a three-year warranty. We'd be remiss not to point out that OCZ 's reliability reputation has a few blemishes, though. Some of the blood on OCZ's shirt comes from its position on the cutting edge; the firm has aggressively adopted new controller technology, often releasing drives long before its rivals—and with much earlier, buggier firmware. OCZ's partners must also shoulder some of the blame. SandForce is responsible for the BSOD bug that afflicted not only OCZ's Agility 3 and Vertex 3, but also similar SSDs from Corsair, Kingston, and others.

We asked OCZ to explain how it performs validation testing on the Everest controller and Octane SSD, and the company told us it's been testing Everest since before the Indilinx acquisition. In addition to performing "a significant amount" of interoperability testing with different platform configurations, OCZ says it uses automated test tools from the likes of Flexstar, Oakgate Software, Lecroy, and Ulink—gear that's also being used by "many of [its] enterprise and OEM customers." Only time will tell if OCZ's efforts have rid the the Octane and its Everest controller of any niggling flaws, and we'll be keeping an eye on the forums to see if end users experience any issues with the drive. If problems do pop up, the onus will be on OCZ alone to fix them.