If you read Dong Ngo's excellent(SSDs) and how to extend their lifespan, then you might be wondering where you and your SSD stand. As Dong explained, SSDs have a finite number of program/erase cycles. That is, you can write data to and erase data from an SSD only so many times before it begins to wear out.
That's the bad news. The good news is the amount of data you need to write to an SSD before it begins to wear out is enormous. In its months-long SSD endurance test, TechReport tested six SSDs and they all made it past the 700TB mark, three topped the 1PB mark and two topped the 2PB mark -- that's PB as in petabytes!
To write that much data to a disk takes a long time -- it took more than 18 months of constant, tortuous writing before TechReport killed all six drives. If you wrote 100GB of data a day, which I doubt you do, it would take you 10,000 days or 27.4 years to write 1PB of data to your SSD.
All of this is to say you probably don't need to worry about the lifespan of your SSD. Your laptop's CPU or its battery will die long before its SSD does. If you are curious to see how much data you've written to your laptop's SSD, however, there is a way to do so on both Windows and MacOS machines.
On your Mac, you can use Terminal to see the amount of data you've written to your drive.
- Open Terminal and enter the "diskutil list" command.
- Find your physical drive on the list, which includes partitions and virtual disks. In my case, my physical is disk0.
- Enter this command: "iostat -Id disk0" or similar (depending on the number for your drive).
You will see three values listed:
- KB/t = kilobytes per transfer
- xfrs = number of transfers
- MB = number of megabytes transferred
The value listed under MB is the total number of megabytes that you have written to your drive from when it was first installed to now. I have written 1,076,395.35MB of data to the SSD I installed in the spring of 2015 on my MacBook Pro. That's just over 1TB of data in about a year and a half.
Sadly, my early-2011 era MacBook Pro will soon be retired because the battery can't hold a charge for much longer than an hour, the spinning beach ball makes frequent appearances and the loud cooling fans spin more often than they rest idle.
Windows doesn't have a built-in way to check the amount of data you've written to disk, so you must instead turn to a third-party application. I use CrystalDiskInfo, a free program that's easy to use.
Launch CystalDiskInfo and it'll display a host of information. For our purposes here, look for two things.
- Check your Health Status. It should say "Good" if all is well with your SSD.
- The value for Total Host Writes is the amount of data you've written to your drive over its lifetime. For my new Windows 10 ($150 at Amazon) laptop, I've written 283GB of data thus far. It's got miles to go before it's put to sleep.
You can also check the status of your Windows laptop's disk by opening the Command Prompt and entering two commands. First, type "wmic" and hit the enter key. Next, type "diskdrive get status" and hit enter again. If everything is good with your system's hard drive, you'll see the Status listed as "OK".