How long, exactly, do SSDs last? It’s a difficult question to answer because estimating an SSD’s life requires taking a whole lot of factors into consideration—type and amount of NAND used in the drive, overall write amplification, read/write cycle, and more. When we did our in-depth examination of how SSDs work a couple of years back, we looked a bit at how those factors affect drive life, but TechReport is going even further than that and has been subjecting six drives to a long-term torture test to actually measure, rather than estimate, the drives’ service life.

The results are impressive: the consumer-grade SSDs tested all made it to at least 700TB of writes before failing. Three of the drives have written 1PB (that’s a thousand terabytes, by TechReport’s decimal reckoning, not 1024TB). That’s a hell of a lot more writes than the manufacturers’ stated drive lifetimes, and that’s good news for SSD-buying consumers.

Performing that many writes takes time—in fact, TechReport has been torturing the drives to death since last August. The six drives chosen to die for science are Corsair’s 240GB Neutron GTX (with 19nm MLC NAND), Intel’s 240GB 335 (with 20nm MLC NAND), two of Kingston’s 240GB HyperX 3K drives (with older 25nm MLC NAND), and two Samsung drives—one 256GB 840 Pro (with 21nm MLC NAND) and one 250GB 840 (with 21nm TLC NAND). The Intel and Kingston drives use SandForce controllers, the two Samsung drives use Samsung's own controllers, and the Corsair drive uses a controller from Link_A_Media Devices.

The tests to which the drives are being subjected are broad in scope, but they involve blasting the drives with incompressible writes (so that their controllers are limited in the advanced compression and de-duplication techniques they can apply to the incoming data). The two identical Kingston drives are also being used to test the difference in drive life brought about by an incompressible workload versus a workload that does allow for compression and deduplication.

In an update posted yesterday morning, TechReport listed the first casualties: the Intel 335, the incompressible workload Kingston HyperX 3K, and the triple-level cell Samsung 840. Intel’s 335 died at around 700TB of writes, while the Kingston drive lasted to a bit over 725TB; the TLC NAND-equipped Samsung 840 gamely soldiered on to past 900TB before dying.

The failure modes of each drive were different as well. The Intel drive entered a self-destruct mode to prevent it from being used after it was no longer able to guarantee its ability to reliably write, while the Kingston HyperX 3K threw SMART errors and vanished after a reboot. The Samsung 840 simply died without warning. However, it’s worth repeating that the failures didn’t occur until the drives had passed the manufacturer’s stated lifetime write limits many times over—it took almost a year of solid torture-test writes to get them to failure.

The other three SSDs are still working and have made it past 1PB of writes, and TechReport’s torture test remains ongoing. However long the drives do end up lasting, it’s definitely long enough to put to rest a lot of fears about current-generation SSD lifetime limits.