OCZ Agility 3 240GB
OCZ is one of the closest SandForce partners and was the first to release products with the SF-2281 controller after its introduction. Right now, the company offers as many as four such product series: Vertex 3 Max IOPS, Vertex 3, Agility 3, and Solid 3. So, the Agility 3 SSD is not the most affordable offering from OCZ although the price per gigabyte of that model is $1.5. The Agility 3 and Solid 3 do not differ much in price, though, so you can’t save a lot of money by preferring the latter.
There is inexpensive asynchronous flash memory inside the Agility 3. Our sample contains 16 Micron 29F128G08CFAAA chips, each with two 25nm semiconductor dies and a capacity of 128 gigabits. So, notwithstanding the low bandwidth of asynchronous memory, the eight-channel SF-2281 controller can enable 4-way interleaving to hide the low performance of the NAND devices.
The Agility 3 offers a total of 256 gigabytes of storage but, like in any other SandForce-based SSD, some of it is allotted for RAISE technology and over-provisioning. 240 GB drives (in reality the actual storage capacity of these drives is 224 "real" gigabytes) have 14.5% of such "hidden" memory, which is exactly the same as in SSDs of smaller size. The ratio is the same with the smaller-capacity products.
OCZ optimizes SandForce’s reference firmware and develops its own software for SSDs. The latest version of OCZ’s firmware is 2.11 but it’s based on SandForce 3.20. OCZ also offers the Toolbox utility which helps you update the firmware, view the SMART data, and perform Secure Erase to restore the SSD's performance to its original level.
OCZ Vertex 3 Max IOPS 240GB
The ordinary Vertex 3 was already tested in our labs and we were pleased with its performance. This time around OCZ offers its fastest SATA 3.0 product for us to test. It is called Vertex 3 Max IOPS. The names are similar, suggesting that the Max IOPS has optimized firmware or something like that, yet the considerable difference in price indicates something more fundamental.
Indeed, the internals of the Vertex 3 Max IOPS are dramatically different from anything we’ve seen so far. The key feature of that model is that OCZ put 32nm flash memory from Toshiba with Toggle Mode DDR interface into it. The memory chips of our sample were marked as Toshiba TH58TAG7D2FBAS9. These are 128-gigabit chips containing four 32-gigabit semiconductor dies each. Thus, although the bandwidth of Toggle Mode DDR MLC flash memory is only 133 MT/s, OCZ hopes to increase the performance by means of 8-way interleaving since there are as many as 64 NAND devices connected to the eight channels of the SF-2281 controller.
Another advantage of using old 32nm memory is its higher reliability. Standard 25nm MLC NAND flash can be rewritten about 3000 times before it becomes unable to store data. The older 32nm memory supports up to 5000 rewrite cycles. It means you can write about 860 terabytes of data to a 240GB Vertex 3 Max IOPS until the end of its service life (this theoretical number is based on JEDEC’s formula).
Every OCZ product based on a second-generation SandForce controller has the same unified firmware. So, the latest firmware for the Vertex 3 Max IOPS is version 3.11 and is based on the SandForce 3.20 code which claims to be more stable than the earlier versions.