Macbook's ssd smart status

Michaluu wrote:

And what might happen if the Available Spare drops under threshold?

In addition to what I posted earlier about the "Threshold" value I'm not certain what the SSD will do if it triggers a "failure" condition as it really depends on the SSD itself. Unfortunately these are Apple branded SSDs and Apple does not share information & details. In theory SSDs are supposed to go into a read-only mode once an SSD has failed. Not having any spare blocks to swap out is fairly catastrophic since the SSD will be unable to write any new data. However, years ago a website conducted a several year torture endurance test of SSDs and found that most of them never went into read-only mode when the SSD failed. Even the SSDs that did go into read-only mode ended up no longer working even for read-only mode once the SSD was power cycled. I had an Apple SSD do just this one time.

I do know that macOS will not install a macOS upgrade if the drive shows a "SMART Failure" as several users have posted about this when attempting to upgrade macOS. I'm not sure about regular macOS updates (aka patches). Of course this assumes the SSD is still working and not in read-only mode.

Unfortunately Apple won't do anything proactively for you or even discuss the strange values (after all you are using an unsupported third party app to get the information). You will need to wait and see what happens. Sometimes ignorance truly is bliss since I'm sure you are now constantly on edge worrying about whether the laptop failing soon. Keep in mind the value is a percentage and not the number of blocks so it is very hard to say how long it will take to drop another percentage point.

Actually DriveDx uses the "smartctl" utility from Smartmontools (you can find it within the DriveDx app bundle).

I'm not sure how these NVMe SSDs work in regards to the Threshold value, but I know on the SATA based drives SMART triggers a drive failure warning whenever the "Value" meets the "Threshold" value. The NVMe based SSDs don't seem to use the same methods of reporting SMART values (or it is hidden).

I do know SSDs can become "confused" at times and I've used the SSD's internal hardware secure erase feature to reset the SSD to factory defaults which usually fixes the odd issues. However, I'm not sure Apple even implements this hardware secure erase in their current NVMe SSDs and there is a risk in performing the secure erase even it if is supported as it could potentially brick the SSD. I have successfully performed the procedure on a couple of 2016 MBPro USB-C models, but on the others I have been unable to access that feature. I don't know if the feature is not enabled or whether our organization's management of these laptops is preventing access to it. I can confirm that I did brick one of the old Apple 2.5" SATA SSD's by performing a hardware secure erase (the enhanced version) so I'm not sure if it was because the SSD had a hardware fault or whether the enhanced secure erase was improperly implemented by Apple. This process does require using a Linux boot disk & utility, but Linux does not work that well on the USB-C Macs.

You'll know if it is a problem once the "Available Spare" percentage drops another point although that may take a while. I still haven't figured out these SMART values on the Apple NVMe SSDs. Their values seem to make know sense when comparing multiple Apple NVMe SSDs. I really haven't checked too many of the 2018+ Macs so I'm not sure if there are any differences in SMART reporting compared to the 2016-2017 models. I haven't gotten too many of the 2018+ models for repair, but I will pay more attention on any that I work on.

It is possible that Apple could later update the firmware which could fix this issue, but I wouldn't count on it.

The best you can do is make sure you have frequent & regular backups. I personally would make sure that at least one backup includes storing important files on external media that can be accessed from any OS in case you don't have another compatible Mac to access a TM backup.

Edit: If the "Available Spares" value drops below the "Threshold" please update this post with what happens as I am very interested. I will update this thread if I have any 2018+ Macs I can check as well.

I guess that is "normal" for those SSDs. Unfortunately letting Apple know and getting them to address it is probably impossible especially if it is not causing a problem with macOS. I guess we'll have to wait and see what happens if the "Available Spares" value drops. I'm wondering if those two values are permanently linked and both values decrease together. Only time will tell.

That is very odd. It doesn't make any sense for the "Threshold" to be that high. I've only seen the "Threshold" value at 10% or less (usually just 1% or 2%). What app did you use to retrieve this information?

Also what is the exact model of this laptop? You can get this information by clicking the Apple menu and selecting "About This Mac".

Edit: I do know that the "Available Spare" and "Percentage Used" values have been all over the place on the laptops I have checked which is a bit concerning to me since with most SSD manufacturers the SMART values are fairly consistent.