My SSD has started showing a "Reliability is Degraded" warning. It does not contain any important data, and I was already considering replacing it with a 2TB NVMe drive. The drive has reportedly had around 285 TB written to it, while its rated endurance is about 180 TBW. Is this warning a sign that it could fail at any moment, or might it reasonably last another month or two while I shop for a replacement? My laptop only supports PCIe 3.0, so would a PCIe 4.0 or PCIe 5.0 M.2 NVMe drive still work in it? I'm also interested in models with a higher TBW rating.
3 Answers
A PCIe 4.0 NVMe drive should work in a PCIe 3.0 laptop, assuming the physical M.2 size, connector, and keying are compatible. It will simply operate at PCIe 3.0 speeds. A PCIe 5.0 drive may also be backward-compatible, but it is usually poor value for an older PCIe 3.0 system and can run hotter. Check the laptop’s M.2 requirements before buying.
The drive is worn beyond the manufacturer’s rated endurance, so the warning means its continued reliability is no longer guaranteed. It has actually lasted fairly well if it has written roughly 285 TB despite a 180 TBW rating. Unfortunately, there’s no reliable way to predict whether it will run for two more months or fail tomorrow. Keep backups and replace it as soon as practical.
It’s worth choosing a reputable SSD rather than the cheapest available model. Differences can include the controller, spare NAND capacity, wear leveling, firmware stability, and whether the drive has DRAM. WD and Samsung have generally been dependable choices, while inexpensive no-name drives can develop controller problems even when their flash memory shows little wear. Regardless of the replacement brand, keep important data backed up because TBW is only an endurance estimate, not a guaranteed failure point.
That makes sense. I hadn’t realized how much data gets written during normal use until I checked the drive’s statistics. I’m looking at 2TB replacements now and want something with a better endurance rating.