It’s a question that has been asked as long as consumer grade SSDs have been around – How long will my SSD last? After all, it’s common knowledge that every SSD has a finite lifespan. It’s just how NAND works. Most SSD manufacturers offer a specification called Total Bytes Written (TBW), which gives an idea of how a drive may last under worst-case-scenario conditions. These specs usually range in the 30-100 Terabyte range, which would be reasonable if you consider how long a drive’s warranty lasts (usually 3 years).
Plenty of people have reported long lasting drives in discussion boards around the net, but without a properly performed test, it’s impossible to know for sure. Thankfully the folks at Techreport have been performing such a test that has been going on for almost a year now. The results are in, and the TL;DR of it is that you probably never have to worry about your SSD not being able to write before you get around to replacing it for other reasons.
They tested a reasonably wide range of drives:
- Corsair Neutron GTX 240GB (19nm MLC) Link-a-Media LM87800
- Intel 335 Series 240GB (20nm MLC) SandForce SF2281
- Kingston HyperX 3K 240GB (25nm MLC) SandForce SF2281
- Samsung 840 Pro 256GB (21nm MLC) Samsung
- Samsung 840 250GB (21nm TLC) Samsung
It’s a good combination, because not only does it test the lifespan capabilities of several different controllers, but the media is different as well. It’s interesting to see if cheaper TLC has a significantly shorter lifespan than MLC, for instance. They even included two Kingston HyperX drives to test the capabilities of SandForce’s compression algorithm – all tests are performed with non-compressible data, but an extra HyperX is included to run 100% compressible data to see if that makes a difference. Typical data is around 50% compressible, so in reality it’s probably somewhere in between.
So after about 10 months of testing, TR has written 700 TB to the drives before some of them started to die. Both SandForce drives running incompressible data died at about 700 TB, and the TLC based Samsung 840 died at just over 900 TB. The rest are still going, and have gone past 1PB by now.
What’s interesting to note is how the drives act when they fail. The Intel 335 went into a “self-destruct” mode, to prevent it from being used since it could no longer write data. The Kingston drive started giving SMART errors before disappearing after a reboot, and the Samsung 840 died without warning.
So far we have a few conclusions to consider:
- The SandForce drives only died in a completely unrealistic 100% incompressible workload. My guess is that the one performing 100% compressible data writes will last the longest – but this is an unrealistic test as well.
- TLC definitely dies faster than MLC. In fact, the only drive not affected by compressibility of data to die was the Samsung 840
- However, while it was the first to die, it died after almost a petabyte of writes. For the average user, this would take a lot longer than 10 months.
So how long will my SSD last?
To find out how long your SSD will last, you’ll need to find out how much data you write to it. As an example, my oldest SSD is about 18 months old. After benchmarking it and using it as an installation drive, it has about 7.2 TB written to it. 7. That’s about 0.4 TB per month. Assuming I keep using it at the same rate, and it lasts for at least 1000 TB, it should be good for… well forever. There’s no way I’ll be able to write enough data to it under normal use, and I expect that to be the case for most people.
Source: Tech Report