# Tell me about solid-state hard drives **URL:** \ **Category:** Factual Questions\ **Created:** [September 16, 2010, 5:19pm UTC](https://boards.straightdope.com/t/tell-me-about-solid-state-hard-drives/553984 "2010-09-16T17:19:38Z")\ **Posts on this page:** 5\ **Page:** 2
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [September 16, 2010, 11:11pm UTC](https://boards.straightdope.com/t/tell-me-about-solid-state-hard-drives/553984/21 "2010-09-16T23:11:15Z")
> [@dracoi](#): > > What I hear regarding SSD life is that each bit can only be written to so many times. Thus, the rapid write and re-write activity of a page file will wear it out more quickly than everyday file access. The drives are designed so that bits that go bad stop being used by the computer; so your whole drive will probably not go bad, but the usable space on it may go down over time. Modern SSD drives have a technology called Wear Levelling which means that this is ameliorated. However, in another forum I frequent - mostly lurk, actually - an engineer said that he uses SSDs for his work and they only last a year or so due to the very heavy usage to which he subjects them. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [September 16, 2010, 11:18pm UTC](https://boards.straightdope.com/t/tell-me-about-solid-state-hard-drives/553984/22 "2010-09-16T23:18:17Z")
> [@TriPolar](#): > > > [@crazyjoe](#): > > > > Perhaps consumer-level devices suffer data loss, but I am not aware of enterprise level devices that don’t overprovision carefully and run tests to make sure that the life of the drive isn’t comparable to a standard disk drive. MTBF rates for EFD are much lower because of the lack of moving parts. > > … > > I have no disagreement with that analysis. As you noted, all enterprise level storage systems should have sufficient redundacy to prevent data loss from any technology. There have been questions about the reliability of solid state devices long term in an unpowered state. Do you know of any conclusive information about that issue? > > Edit: I should have noted that ‘cost effective’ would evaluate differently for installation of new storage devices vs. replacement of existing units. there were some early SSDs that had firmware bugs that could result in (complete) data loss under very certain circumstances, but I think those have long been fixed. flash memory _does_ have a finite number of times it can be erased and rewritten, but even consumer-grade SSDs will last a good number of years before this limit is reached. and when it does hit this limit, you don’t start losing data; the drive just becomes read-only. ---
**Author:** ![crazyjoe](https://avatars.discourse-cdn.com/v4/letter/c/f14d63/32.png) [@crazyjoe](https://boards.straightdope.com/u/crazyjoe)\ **Post date:** [September 17, 2010, 3:28am UTC](https://boards.straightdope.com/t/tell-me-about-solid-state-hard-drives/553984/23 "2010-09-17T03:28:18Z")
> [@Quartz](#): > > > [@dracoi](#): > > > > What I hear regarding SSD life is that each bit can only be written to so many times. Thus, the rapid write and re-write activity of a page file will wear it out more quickly than everyday file access. The drives are designed so that bits that go bad stop being used by the computer; so your whole drive will probably not go bad, but the usable space on it may go down over time. > > Modern SSD drives have a technology called Wear Levelling which means that this is ameliorated. However, in another forum I frequent - mostly lurk, actually - an engineer said that he uses SSDs for his work and they only last a year or so due to the very heavy usage to which he subjects them. Thank you, “wear levelling” is the term I could not bring to the tip of my brain earlier. I’d be curious whether your forum acquaintance is using a consumer-level SSD (and I like to think that the D stands for “device” instead of disk or drive) or an enterprise level one, and what he is using it for. AS I said, companies typically test these things with insane duty cycles for enterprise usage, so they can run at 80 - 90% throughput for almost 5 continuous years. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [September 17, 2010, 4:37am UTC](https://boards.straightdope.com/t/tell-me-about-solid-state-hard-drives/553984/24 "2010-09-17T04:37:53Z")
> [@crazyjoe](#): > > Thank you, “wear levelling” is the term I could not bring to the tip of my brain earlier. I’d be curious whether your forum acquaintance is using a consumer-level SSD (and I like to think that the D stands for “device” instead of disk or drive) or an enterprise level one, and what he is using it for. AS I said, companies typically test these things with insane duty cycles for enterprise usage, so they can run at 80 - 90% throughput for almost 5 continuous years. I’d like to hear more about you enterprise configuration. I deal with a lot of systems that use a large volume of disk for query results, that might not be the best application of SSD (I like to think the D stands for doohickey), but they use many times that amount of storage for databases that are frequently extended, but don’t have that many inserts (its tricky though, lots of fields change with dynamic allocation). There’s also an increased use of image files for client applications that don’t change very often either. Many of the customers are very conservative, so they’ll probably switch to SSD when two more generations of technology are developed, but the new sites (or the old ones that finally can’t get their hardware serviced anymore) usually upgrade to newest technology. What OS are you using, hardware, number of simultaneous users, etc.? If you can talk about any details. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [September 17, 2010, 6:54am UTC](https://boards.straightdope.com/t/tell-me-about-solid-state-hard-drives/553984/25 "2010-09-17T06:54:25Z")
> [@crazyjoe](#): > > > [@Quartz](#): > > > > Modern SSD drives have a technology called Wear Levelling which means that this is ameliorated. However, in another forum I frequent - mostly lurk, actually - an engineer said that he uses SSDs for his work and they only last a year or so due to the very heavy usage to which he subjects them. > > Thank you, “wear levelling” is the term I could not bring to the tip of my brain earlier. I’d be curious whether your forum acquaintance is using a consumer-level SSD (and I like to think that the D stands for “device” instead of disk or drive) or an enterprise level one, and what he is using it for. AS I said, companies typically test these things with insane duty cycles for enterprise usage, so they can run at 80 - 90% throughput for almost 5 continuous years. I’m afraid I don’t know what exactly he does with the drives, nor what grade he uses, but I’d guess that they were the enterprise ones given that he said he worked at the time - we’re talking a year or so ago - for Intel or Microsoft (I forget which). [Previous page](https://boards.straightdope.com/t/tell-me-about-solid-state-hard-drives/553984.md?page=1)