Will 512GB SSD "wear" longer than 256GB ?

We know hard drives work that way. If data is there, those areas of the drive never change until you delete some of that data so it can be used for something else.

It would seem somewhat logical for an SSD to move things around on its own to prevent part of the drive from being "unused" compared to the rest of it, but how would you do that without the following?

1) Since drives routinely have cache data at minimum written every time you use your computer, it would create a noticeable lag in performance to have the drive redistributing live data on its own. Need to read in a 500 MB Photoshop layered file? Well, hold on to your britches there for a few minutes, I just happened to be moving that one at the time you asked to open it.

2) They're incredibly fast reading, but SSDs don't write all that fast. At least the ones we have don't write much (if any) faster than the 7200 rpm drives that are also in our Mac Pros. And they're pretty darn good drives by rating.

3) Users would NOT like a drive that wears itself out faster by writing data on its own at random intervals.

All of this doesn't mean they don't already do this. I haven't looked that deeply into the subject. But I'd be surprised if they do.

All newer SSD's (like within the past few years or so) do wear leveling. Said another way, it keeps track of what parts of the drive have been written to, and those that have not, or not as often. It automatically distributes the writes so the drive wears out in an even manner.

So, technically, a 512GB should last twice as long as a 256GB drive. But that depends on how you use it. If, for example, you fill 350GB of a 512GB drive with data that essentially never gets deleted, then the remaining 160GB of space will bear the brunt of the leveling while the rest of the drive remains in practically new condition.

I do a fair share of video/movie/graphics editing/rendering and can easily amass 100 - 150 GB of temporary files while I'm working on a 1 hour HD project - which will all be deleted after the project is done and I save a copy of it on an external drive. That means I do a lot of erasing/rewriting to large chunks of real estate and I have not been able to find information on how well an SSD does for that kind of "abusive" work. Because of that, I'm still using a spinning drive in my iMac (where I do this stuff). My MBP has a 256 GB SSD from OWC which is now almost 4 years old; however, that only gets light use (browsing online, playing a game or two).

(Sorry for the tangent here, this does not really address the original question at all.)

Of course, always keep a backup whatever drive you use. In the event of end-of-life the SSD basically becomes read-only, right? Can you boot from a read-only end-of-life SSD drive? When a spinning mechanical drive fails, if becomes a door stop.

I guess virtual memory usage on the hard drive would also impact the lifetime of the SSD as well, so it would be a good idea to max out your physical RAM if you are using an SSD for the primary boot drive which is used by OS X for swap space to prolong the life of the SSD.

Personally, with iMacs being so difficult to repair, if I was dealing in

work that was routinely reading/writing/erasing huge chunks of data,

I would put all that data on an external drive (either USB3 or Thunderbolt)

and locate any caches there as well. I would then just keep the normal stuff

on the internal SSD that does not do large amounts of reading/writing/erasing.

This way, when an external drive "wears out", you just plug in a new one

instead of hauling your iMac in for repair.

It depends on which iMac model year, some may be upgradeable for the skilled DIY-er. OWC offers a service, but the process is really not that hard, I recently installed RAM and SSDs in both a 21.5" and a 27" iMac, 2010 vintage. I had some prior experience over the years with upgrading a G3 Desktop, G4 Tower, and a MacBook laptop, hard drive and RAM, etc, but the iMac is totally different from those older machines. The iMac models I have were not that hard to open up and access the internal drive bay. OWC has videos on how this is done and sells complete packages with all the tools you need, for those who wish to attempt to DIY, for example:

https://eshop.macsales.com/item/OWC/KITIM09HE1TB/

The SSD is much faster when booting and launching applications, very quiet and cool compared to the 7200 RPM original drive. Not sure what the lifetime of the SSD will be, this is my first adventure into the SSD realm, but I have had to replace mechanical drives several times over the years roughly every 3-5 years (in-line with the warranty expiration of the drive) anyway. The process goes smoothly when you have a recent backup.

The 2010 vintage iMac I have is pre-Thunderbolt and limited to USB 2.0 and FW 800 external ports, much slower than USB 3.0 or Thunderbolt external drives, but I mainly use the external drives for backup only, don't really care about how slow they are.

Glen Doggett wrote:

It depends on which iMac model year, some may be upgradeable for the skilled DIY-er. OWC offers a service, but the process is really not that hard, I recently installed RAM and SSDs in both a 21.5" and a 27" iMac, 2010 vintage. I had some prior experience over the years with upgrading a G3 Desktop, G4 Tower, and a MacBook laptop, hard drive and RAM, etc, but the iMac is totally different from those older machines. The iMac models I have were not that hard to open up and access the internal drive bay. OWC has videos on how this is done and sells complete packages with all the tools you need, for those who wish to attempt to DIY, for example:

...

Still means taking the machine out of service for some period of time,

whether doing it yourself or to a repair facility. The time it would take to

get a replacement drive would be the same as an external and you would be

using the external once you unboxed it, instead of taking the time to rip a machine apart

and putting back together.

They should have similar lifespans, the 512 holds more stuff, but it does not last longer.

And are there any statistics yet for the actual "life span" for any specific size of SSD for any specific type of usage?

I googled this for you:

https://ssd-life.com/eng/how.html