Activity Monitor: data written and read. Meaning?

When I open Activity Monitor and I choose the disk tab I see at the bottom right numbers (GB) associated with data written and read. What is their meaning? Data written and read since I bought my Mac and I started using my SSD?


Thanks

Maurizio

Posted on Sep 20, 2023 11:45 PM

Reply
2 replies
Question marked as Helpful

Sep 22, 2023 2:02 AM in response to maurizio277

maurizio277 wrote:

Thanks. I do not have any problem, yet. My iMac is 1 year old and my MacBook Air is 3 months old. Of course I am not worried....

Respectfully, it appears you what to advert problem which is commendable.


Pursuing this way of thinking is akin to " following a rabbit down the a rabbit hole " - you will never catch it.


Problems do not need to looked for. They will find you soon enough.




I was just curious since I read all those posts and seen some videos where they discuss estimates of life for SSD.

Suggest disregarding the Social Media sites in regards to SSD Drives.


At Best they are only one person writing with out any Technical Basis


In the 20 years of using Apple Laptops and Desktops, I have had only two hardware issues.


The first was the very first Intel Based 15" Laptop where the Video Card failed and the second was when I ( my actions ) fried the LogicBoard. That was on the first Fan-less MacBook 12" when running it to a HD TV via HDMI for hours on end



Is the total of "MB written since first purchase of Mac" kept somewhere and available with the appropriate tools or through some terminal command? Just to have an idea....


I am not sure there is any Third Party Application or Terminal command that can capture the Full History of the number of Read / Writes that have occurred to the Internal Drive


For that specific answer, I have put out a message to " My Go To " hardware expert to have look at this.


If were are fortunate, they will make an appearence in your question and perhaps offer some additional insights


15 replies

Sep 21, 2023 2:48 AM in response to maurizio277

maurizio277 wrote:

When I open Activity Monitor and I choose the disk tab I see at the bottom right numbers (GB) associated with data written and read. What is their meaning? Data written and read since I bought my Mac and I started using my SSD?

Thanks
Maurizio

As far was I know, Activity Monitor >> Disk Tab is supplying you with the Amount of Data being Read from your Internal Drive and Written to your Internal Drive


It does Not Measure the Data Read or Written to an External Drive


To measure the performance of an External Drive Read / Write Speed would require a Separate Application.


Some are available from the Apple Apps Store like Black Magic Speed Test and others

Sep 21, 2023 3:27 AM in response to maurizio277

maurizio277 wrote:

Thanks!

A - Welcome


I understand that, but I was referring to my internal SSD (I do not use an external SSD). Would the information provided by Activity Monitor tell me how many GB I wrote to my internal SSD since when I started to use it (i.e. since when I bought my MAC), roughly?


A - No it will only show the current Read and Writes to the Internal Drive since the computer was started from the last Off Position to the ON Position


A - It will not have a Full History since the machine was First Purchased .


A - If I may request, Is there a special concern about the Internal Drive


A - Internal SSD Drives from Apple are pretty well Tested to last many years without any Malfunctions


A - I have three different M1 / M2 Apple computers.


A - The Oldest was purchased in 2020 and it is still works as good as new.


A - Is is even better since upGrading from macOS 11 to macOS 13.5.2 and expect to upGrade to macOS 14 Sonoma on Sept 26 this year


Sep 21, 2023 9:59 AM in response to P. Phillips

Thanks. I do not have any problem, yet. My iMac is 1 year old and my MacBook Air is 3 months old. Of course I am not worried....


I was just curious since I read all those posts and seen some videos where they discuss estimates of life for SSD.


Is the total of "MB written since first purchase of Mac" kept somewhere and available with the appropriate tools or through some terminal command? Just to have an idea....


Maurizio

Question marked as Helpful

Sep 22, 2023 2:02 AM in response to maurizio277

maurizio277 wrote:

Thanks. I do not have any problem, yet. My iMac is 1 year old and my MacBook Air is 3 months old. Of course I am not worried....

Respectfully, it appears you what to advert problem which is commendable.


Pursuing this way of thinking is akin to " following a rabbit down the a rabbit hole " - you will never catch it.


Problems do not need to looked for. They will find you soon enough.




I was just curious since I read all those posts and seen some videos where they discuss estimates of life for SSD.

Suggest disregarding the Social Media sites in regards to SSD Drives.


At Best they are only one person writing with out any Technical Basis


In the 20 years of using Apple Laptops and Desktops, I have had only two hardware issues.


The first was the very first Intel Based 15" Laptop where the Video Card failed and the second was when I ( my actions ) fried the LogicBoard. That was on the first Fan-less MacBook 12" when running it to a HD TV via HDMI for hours on end



Is the total of "MB written since first purchase of Mac" kept somewhere and available with the appropriate tools or through some terminal command? Just to have an idea....


I am not sure there is any Third Party Application or Terminal command that can capture the Full History of the number of Read / Writes that have occurred to the Internal Drive


For that specific answer, I have put out a message to " My Go To " hardware expert to have look at this.


If were are fortunate, they will make an appearence in your question and perhaps offer some additional insights


Sep 22, 2023 7:55 AM in response to maurizio277

maurizio277 wrote:

Thanks! I understand that, but I was referring to my internal SSD (I do not use an external SSD). Would the information provided by Activity Monitor tell me how many GB I wrote to my internal SSD since when I started to use it (i.e. since when I bought my MAC), roughly.


Activity Monitor does not show this, and I am aware of no other built-in displays of this information.


Apple does not publish the specific format of their command responses for drive write activity, nor does Apple publish the expected lifetime of the storage devices. Which means that tools accessing that data are potentially making guesses about what is shown.


To get what is usually purportedly the drive information, one choice is smartmontools. You’ll need to download Xcode or the command line tools and either build that, or use homebrew to install that tool, or find an existing build and use that.


From smartmontools and the command line, you’ll get what is believed to be the write activity and the remaining lifetime percentage.


Here is a general overview of the data:

https://media.kingston.com/support/downloads/MKP_521.6_SMART-DCP1000_attribute.pdf


I haven’t gone looking for this particular detail, but DriveDx is another potential option. That tool is more readily available for use.


Here is some reading: https://eshop.macsales.com/blog/80464-how-to-check-your-mac-ssd-health/


PS: It’s “Mac”, not “MAC”. In common technical discussions, “MAC is an acronym for media access control, which something very different from “Mac” which is usually a computer.

Activity Monitor: data written and read. Meaning?

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