#Ssd health osx how to#

One thing to note, many NVMe SSDs can have significantly largeĪmounts of built in DRAM. Actually, reading through that entire page, without precise manufacturerĭefinitions nearly every value that may be read in SMART status could be ?. Significantly lower or even higher? It seems no one really knows for sure at Value, perhaps all the readings are bogus. So, it would appear that unless Apple has released the precise details of this These values may significantly vary between different manufacturers and drive models and should NOT be compared with other devices or other vendors.' The exact meaning of raw value often considered as trade secret. The drive manufacturer defines the meaning of this value (but often corresponds to counts or a physical unit). Sometimes different parts (high word, low word, etc) of raw value contain different kind of information. Raw measured values (provided by a sensor or a counter) are stored in this field. 'Raw' value that all these apps use to determine total bytes writtenĬan be cloaked in mystery especially with a brand new drive. I found an interesting piece on the DriveDx site. But with the tools available, there is equipoise, so it's up to Apple to set the record straight, and address if theres a problem.

I would like the truth to be that this is all a big misunderstanding and the SSDs are working within reason.

#Ssd health osx how to#

But even assuming Activity Monitor and iostat are correctly reporting how much the OS is writing, its the SSD itself which is deciding how to manage its data, and its entirely possible that its firmware is causing more writes than is expected. What you said about the sector size is very interesting, ill have to crunch the numbers and see how that effects what ive measured over the past week. Is Big Sur going berserk with writes? Is anything correct?Ĭoncerning the accuracy of the measures, likewise, I found that Activity monitor and 'iostat -Id disk0' report stats that don't match to smartctl and in fact, iostat and activity monitor don't match up perfectly to each other, even though they're both Apple's tools for reporting read/writes since uptime.Īctivity monitor reports about 1.6TB written over 11 days, which is still a lot even though it's a lot less than whats coming up via smartctl. Is the total calculation incorrect? Is the sector size/unit size even correct? The math says the total number of writes should be ~120 GB, which isĪwfully close to a difference factor of 1000. The M1 SSD sector size is 4096 (if that is even being reported correctly. Just looking at your data, units/sectors written being reported is 24 MB. Knows how many writes (or reads) there really are being done. SMART status available and formats of the data and how they should beĢ) While Activity Monitor has been around a long time, I believe thereģ) Until there are reliable tools to measure the usage, no one really Written times sector size do not add up to total bytes written.ġ) The SSDs in the M1 machines are not totally documented in terms of That make sense to give the totals they are getting, i.e. One said about 30 GB was written another said only about 10 GB was writtenĪlso, some of the SMART tools themselves do not have numbers Showed nearly 70 GB of writes, but only 500 MB swap was used so it is notĪ RAM swapping issue and based on Activity Monitor, the apps that were used neverĭid more than a couple GB of writes. Said there were 40 GB of writes and smartctl actually reported thatĪnother example today, I did a photo processing session and Activity Monitor As a matter of fact, one day, Activity Monitor To what Activity Monitor is saying for the number of bytes, it doesn't jive SMART tools all of which gave different usage data. I have been investigating this 'issue' as well. SMART overall-health self-assessment test result: PASSEDįor one, reads don't matter with SSDs, only writes. St Op Max Active Idle RL RT WL WT Ent_Lat Ex_Lat Optional Admin Commands (0x0004): Frmw_DL Smartctl 7.2 r5155 (local build)Ĭopyright (C) 2002-20, Bruce Allen, Christian Franke, = START OF INFORMATION SECTION = 2) What is this SSDs actual lifetime writing ability? 3) When is my SSD actually expected to fail 4) What is Apple's position on this and what action are they taking to address it? My questions are 1) is smartctl correctly reporting SSD data write usage. Assuming this SSD has a lifetime ability to write 150TB, this disk is expected to have issues in approximately 2.8 years. The the smartctl tool reports that my M1 MacBook Air has written 12.3 TB since being purchased in mid-December. In the past few weeks it's been reported that M1 SSDs are writing a sufficient amount of data to their drives such that it could render the drive at its end of life in a few years.