The playbook for SSDs is pretty well established. Controller updates are few and far between, so new drives typically combine existing technology with flash fabbed on a finer manufacturing process. That's not the most exciting recipe, but it makes sense. These days, most folks want SSDs to be cheaper rather than faster. Transitioning to finer lithography is the best way to lower the all-important cost per gigabyte.
OCZ followed that formula when it released the Vertex 450 earlier this year. That drive paired the Indilinx Barefoot 3 controller from OCZ's Vector SSD with newer 20-nm NAND. Now, OCZ is back with the Vector 150, which mates the Barefoot chip with the latest 19-nm flash.
To be fair, there's more to the Vector 150 than a NAND upgrade—and more to this story than the drive itself. Now that I've teased some intrigue, let's dive into the details.
OCZ's own Indilinx Barefoot 3 controller sits inside the Vector 150's 7-mm case. The chip is the same M00 revision used in the original Vector rather than the slightly down-clocked M10 variant employed by the Vertex 450. Apart from the clocks, the two chips are pretty much identical.
Like most contemporary SSD controllers, the Barefoot 3 has a 6Gbps Serial ATA interface on one end and eight parallel NAND channels on the other. The controller can address up to four individual flash dies per channel, making 32-die configurations ideal for peak performance. It also has an AES encryption engine onboard. That encryption block went untapped in the original Vector, but the new model can scramble bits on the fly using a 256-bit AES algorithm.
After loading its previous Barefoot 3 drives with Intel and Micron flash, OCZ has switched to Toshiba Toggle DDR NAND for the Vector 150. The change is notable because, during last month's investor conference call, CEO Ralph Schmitt said OCZ was "still struggling to secure flash allocation." That struggle primarily affected OCZ's client SSD business, according to Schmitt, who also said the firm had trouble getting NAND at competitive prices. The situation was serious enough that OCZ declined to provide future guidance due to "current uncertainty with credit and supply."
We asked OCZ how that uncertainty might affect the Vector 150. The firm told us the switch to Toshiba NAND is part of the solution to its supply problems, and that Toshiba has been a "good partner" for its enterprise SSD business. Flash supply shouldn't be a problem for the Vector 150.
Unfortunately, moving to Toshiba NAND cuts OCZ out of the packaging. In the past, OCZ has purchased flash by the wafer and then handled the cutting and packaging of individual dies internally. That approach can lower costs, facilitating lower drive prices, but the Toshiba NAND comes pre-packaged.
The NAND packages split 128Gb (16GB) between dual 64Gb (8GB) dies. As with the flash in most consumer SSDs, there are two bits per cell—it's MLC NAND, in other words.
|Max sequential (MB/s)||Max 4KB random (IOps)||Price||$/GB|
|120GB||16 x 64Gb||550||450||80,000||95,000||$130||$1.08|
|240GB||32 x 64Gb||550||530||90,000||95,000||$240||$1.00|
|480GB||64 x 64Gb||550||530||100,000||95,000||$500||$1.04|
Remember what I said about 32-die configurations being ideal given the Barefoot 3's channel configuration? The Vector 150's performance ratings largely bear that out. The 120GB model has only 16 dies, and its sequential write speed is 80MB/s slower than that of the 240 and 480GB models. Our 240GB sample has the same write speed rating as the 480GB drive. Oddly, though, its random read rate is slightly lower.
OCZ's earlier Barefoot 3 SSDs have come in 128, 256, and 512GB flavors, but the Vector 150 is limited to 120, 240, and 480GB. The drives have the same amount of flash as their predecessors; they just devote more of it to so-called spare area accessible only to the controller. OCZ did this in part to improve performance with sustained workloads. Allocating additional spare area provides a larger pool of empty NAND pages for incoming writes.
The spare area was also increased to improve endurance. The larger the overprovisioned area, the more flash reserves are available to replace blocks that have gone bad due to normal wear. According to OCZ's specifications, the Vector 150 is good for 50GB of writes per day for five years under typical client workloads. The Vertex 450 and the original Vector are rated for only 20GB per day. You can read more about how many writes modern SSDs can actually take in our ongoing endurance experiment.
As the Vector 150's endurance rating implies, the warranty lasts for five years. OCZ's reliability reputation is a little tarnished, though. Amazon and Newegg user reviews for the Vertex 450 and the original Vector are peppered with complaints about errors and premature failures. Online reviews should be taken with a sprinkling of salt, of course, but the numbers are worth noting. The table below summarizes the "star" ratings associated with the user reviews of a bunch of modern SSDs.
|Corsair Neutron GTX||8%||0%||4%||0%||88%||26||1%||1%||4%||5%||88%||75|
|Intel 335 Series||0%||3%||5%||13%||80%||40||7%||1%||2%||5%||84%||95|
|Intel 520 Series||6%||3%||4%||12%||73%||203||7%||3%||3%||7%||81%||115|
|Samsung 840 Series||3%||2%||2%||14%||79%||1221||7%||2%||4%||13%||74%||734|
|Samsung 840 Pro||2%||1%||2%||9%||86%||903||5%||2%||3%||8%||82%||865|
|OCZ Vertex 450||36%||0%||0%||14%||50%||14||38%||13%||6%||0%||44%||16|
The OCZ SSDs clearly have more negative reviews than their peers. Just look at all those one- and two-star ratings.
In the past, OCZ has attributed Vector complaints to issues addressed by a firmware update issued in March. However, there are plenty of reports of failed Vector drives from just the past few months. The Vector's firmware fixes were rolled into the Vertex 450, but that drive also has numerous reports of premature failures. In fact, the percentage of negative Vertex 450 reviews is even higher than for the Vector, albeit with a much smaller sample size.
OCZ says its internal data points to a defect rate of "around 1%," which sounds a lot better than the figures listed above. If only that claim made me feel more confident. When OCZ introduced the Vector, it said bringing controller and firmware development in house would allow it to avoid the reliability issues that plagued some of its early SandForce-based products. So far, the anecdotal evidence suggests that OCZ SSDs are more problematic than their peers.
Still, OCZ does have a reputation for producing wicked-fast SSDs. Let's see how this puppy performs...