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The petabyte club
As their comrades fell around them, the Corsair Neutron GTX, Samsung 840 Pro, and compressible Kingston HyperX 3K drives soldiered on to 1PB without issue. That's kind of miraculous, really: a bunch of consumer-grade SSDs withstanding one freaking petabyte of writes. None of these drives are rated for more than 200TB.

Reaching such an important milestone warrants a closer look at the health of the remaining candidates, especially since one of them might not be with us for very long. Along the way to 1PB, the second HyperX posted a pre-failure SMART warning.

Thanks to its compressible payload, this HyperX logged only 716TB of flash writes for 1PB of host writes. Don't read too much into the magnitude of the savings, though. The stream of sequential writes in our endurance test isn't indicative of real-world client workloads. Those workloads write far too slowly to stress SSD endurance in a reasonable timeframe.

Apart from its declining life indicator, the compressible HyperX is in excellent shape. It's logged only two reallocated sectors and no program or erase failures so far. The flash seems to be in much better condition than that of its incompressible twin, which had hundreds of reallocated sectors and lots of program and erase failures with a similar volume of flash writes. The difference between the two configs suggests there may be some variance in flash endurance from one SSD to the next, even within the same family. Our sample size is far too small to draw a definitive conclusion, though.

Given how the HyperX is designed to behave, death probably isn't imminent. I wouldn't expect a failure until the number of reallocated sectors starts increasing substantially.

Next up: the Samsung 840 Pro.

After the 840 Series' sudden demise, it's hard to know what to expect from the Pro. This drive has the same SMART attributes as its TLC counterpart, including the wear leveling count that's supposed to be related to health. The thing is, that attribute hit its lowest point after 400TB of writes, and Samsung's SSD utility said the drive was still in good shape. SSD Magician indicated that everything was cool at 1PB, too, although the shrinking reserveĀ  of used blocks points to an increase in reallocated sectors.

The number of reallocated sectors started ramping up after 700TB, hitting 1836 at the 1PB mark. Based on its 1.5MB sector size, the 840 Pro has retired 2.7GB of its total flash capacity. There's plenty left, but whether we burn through it all remains to be seen.

Our last survivor is Corsair's Neutron GTX. Several of this drive's SMART variables are obfuscated by vague, "vendor-specific" titles, but Corsair's Toolbox utility identifies attribute 231 as "SSD life left." HD Sentinel lists the same attribute as temperature, but the profile fits what we'd expect from a lifespan indicator, albeit one that thinks the Neutron is going to be around for a very, very long time.

If the current rate of decline continues, the life attribute won't hit zero until after more than 4PB of writes. That seems a tad optimistic for a consumer-grade SSD, so we've asked Corsair to clarify exactly how the value is calculated. It's possible the slope could steepen in response to reallocated sectors. The drive hasn't logged any of those yet, though.

Before moving on to our performance results, I should clarify that simply writing a petabyte isn't sufficient for entry into our exclusive club. After reaching that milestone, the survivors faced another unpowered data retention test. They were left unplugged for seven days, and they all returned with our 200GB test file fully intact.

Now that we know which SSDs lived and which ones died, let's see if any of them slowed down over the last stretch.