When I got my first SSD a few months ago I had discussions with the technical support section of the manufacturer Corsair, as to whether I might have damaged it because I had defragged it a couple of times in ignorance. This was Corsair's reply in part:
1. The SSDs we develop will last up to 20 years even if you write more than 20GB of information a day (which is well beyond the normal user). I believe you will replace your system long before you replace the SSD.
"Up to?" What do they
guarantee? Intel spec'd their very popular X25-M series for
a minimum of 5 years at 20 GB/day, and this hasn't changed with their more recent 510 and 520 series. ISTR that the latest batch of SSDs are rated for 3,000 program/erase cycles vs 5,000-10,000 in the drives one generation back. My understanding is that they partially make up for this decreased longevity by using data compression, but all the advantages of data compression go away if you use encryption with programs like Bitlocker or Truecrypt. I'd ask Corsair what their minimum guarantee is for both compressible and uncompressible data, for a drive formatted to full capacity, as well as how much overprovisioning they use, and what technology they're using.
As I mentioned in an earlier post, there are whitepapers on intel.com where they talk about end-user overprovisioning to increase the longevity, in addition to the overprovisioning that comes from the factory. The one for the X25-M series uses the 160 GB model as an example and gives 29 TB for the expected endurance OOTB, increasing to 68 TB with 16 GB overprovisioning and so on. But Corsair is claiming almost 150 TB for their drives with no overprovisioning, using I presume newer technology that has fewer write/erase cycles than the 34nm X25-M drives? Interesting...
As I wrote earlier, most people will just format to maximum capacity and not overprovision, which means that things like hibernation and hybrid sleep can use up the majority of their writes all by themselves going by the Intel numbers. Though pointless, I would guess defragging is less of a concern WRT lifespan because it's done much less frequently than sleeping, and once defragged, files stay defragged. So it would be expected that an initial defragmentation would move a lot of data around, but subsequent ones would move less.
I always recommend disabling hybrid sleep on SSDs unless you really need it, and if you're on a laptop, you don't thanks to the battery, and on a desktop equipped with a decent UPS like my APC XS-1500 running Powerchute, you don't, because the UPS will wake it from regular sleep to hibernate in the event of a prolonged power outage. This saves me 10s of GBs of completely pointless writes per day.
