Five SSD flavors
Our endurance experiment covers five distinctly different SSD configurations in the 240-256GB range. We'll start with the latest version of Corsair's Neutron Series GTX. We reviewed an earlier variant of this drive last year, and the Link_A_Media Devices controller hasn't changed. However, Corsair has since upgraded the flash from 26-nm Toshiba MLC NAND to smaller 19-nm chips.
The Neutron's new NAND comes with an accompanying price cut, bringing the GTX down to $220. That's pretty affordable considering the five-year warranty; most SSDs in this price range are covered for only three years. Unfortunately, Corsair doesn't list an official endurance specification for the Neutron GTX.
Given the 240GB storage capacity, one might assume Corsair has dedicated additional spare area to replace bad blocks. As far as we're aware, though, the drive has the same ~7% overprovisioning as 256GB drives. In this case, another ~7% of the raw flash capacity is dedicated to parity data associated with the controller's RAID-like redundancy scheme, which provides an extra layer of protection against physical flash failures.
Users can monitor the Neutron GTX's health using Corsair's SSD Toolbox software. The application is relatively new, and the interface could use a little more polish. It'll do for our purposes, though. The information section displays the total host writes, and there's a SMART section that reads the drive's attributes. The host writes measure is linked to SMART attribute 241, which keeps tabs on the number of LBAs written. Attribute 231 is the generic wear indicator, while attribute 5 tallies bad blocks.
The next SSD on our list is Intel's 335 Series. Behold its stark metal body:
The 335 Series pairs SandForce's SF-2281 controller with 20-nm MLC NAND produced by IMFT, Intel's joint flash venture with Micron. Like the Neutron GTX, the 335 Series derives 240GB of storage from 256GB of NAND. Part of the "missing" capacity is devoted to RAISE, the RAID-like redundancy feature built into the SandForce controller.
Intel says the 335 Series can endure 20GB of writes per day for the length of its three-year warranty. That rating applies to typical client workloads, and it adds up to 22TB overall. Our endurance test will be able to push past the specified limit in short order.
At $220 online, the 335 Series 240GB is a tad expensive in light of its pedestrian warranty coverage. You're paying a premium for the Intel badge—and for the excellent SSD Toolbox software.
Despite bearing the same name as Corsair's utility, Intel's software is much nicer. The main screen doesn't list host writes, but it does characterize drive health, and it estimates how much life is remaining. Again, clicking the SMART button brings up an attribute tracking panel.
The Intel 335 Series tabulates writes in several ways. Attribute 225 measures host writes, 233 tracks the number of LBAs written, and 249 reports NAND writes in 1GB increments. There's also a media wear indicator, attribute 233, that ticks down from 100 as the NAND erodes. Once again, the number of retired blocks is covered by attribute 5, a.k.a. the reallocated sector count.