System Data & "Memory Pressure"

[ufgatorvet]

2017 27" iMac.base model 8GB RAM, 1 TB Fusion drive.

Is this "normal" for "system data" to be using this much space? I've noticed recently that this computer has been starting to slow down ...

Thanks so much,

 

[ufgatorvet]

On a pseudo-related topic, Apple said that this "memory pressure" graph helps to determine if increasing RAM would be beneficial. This is the base model 8 GB.

Would increasing the RAM potentially help in my day-to-day usage and speeding things up?

On the surface, it doesn't look like it. Granted, this is a short time period snap shot. Is there a way to look at the "memory pressure" over the last week or month, or year?

I do not use Final Cut, video editing, etc. I do a lot of spreadsheets and accounting things and primarily a "consumer" of all things internet (youtube, safari, youtubetv, Apple Music, etc).

Thanks again,

 

[wilberforce]

It is very easy and cheap to add RAM to a 27" iMac. Almost a no-brainer. Pretty surprised you still only are using 8GB. Will cost about $20 to add another 8GB. It would be a significant improvement. Nowadays just running a bunch of tabs in a web browser can suck up a lot of memory.

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Slowness is likely due to the Fusion drive, which are slow and prone to failure compared to SSD.
Many people have opted for working out of an external SSD instead. Best would be a TB3 drive like the 1TB Samsung X5, or the 1TB OWC drive for about $300, but I don't know if you want to spend that much:

OWC Envoy Pro FX Thunderbolt 4 SSD – Fast External Storage

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An External SSD Gave My iMac a New Lease on Life - TidBITS

Prices for SSDs and Thunderbolt 3 enclosures have plummeted, so Glenn Fleishman finally bit the bullet to upgrade the storage for his lagging 2017 iMac. Doing so probably extended the useful lifespan of his iMac by years.

tidbits.com

For about $100 you can get a 1TB Samsung T7, but it is not as fast.

Large system data may be things like time machine snapshots or caches, hard to tell.

 

[ufgatorvet]

Thank you for your thoughts and suggestions. Very helpful.

I appreciate your time!

 

[wilberforce]

Thank you for your thoughts and suggestions. Very helpful.

I appreciate your time!

I don't know what MacOS you are using, but this may be useful, if you use time machine:

View APFS snapshots in Disk Utility on Mac

In Disk Utility on Mac, view a list of APFS snapshots, copy information about the snapshots, and delete them.

support.apple.com

Obviously, make sure you have a backup somewhere else before deleting snapshots on the internal drive.

btw, some people save some money by putting together their own TB3 external SSD, by getting a TB3 enclosure and putting an NVMe blade inside. If cost is an issue, you can research doing this. Just pointing out this option exists, too.

 

[Fishrrman]

I'm thinking that the SSD portion of the fusion drive (which is a 24gb or 32gb SSD) is becoming "saturated", perhaps causing the slowdowns.

Some would pry open the iMac and start fooling with the drives inside, but I won't recommend that.

Rather, I'd suggest you get a USB3.1 gen2 SSD (or put one together yourself), plug it into one of the USBc ports on the back, and set it up to be the "new EXTERNAL boot drive".

You DO NOT WANT a USB3 SSD for a 2017 iMac.
You DO WANT a USB3.1 gen2 SSD, which is almost twice as fast. The 2017 was the first iMac to have USBc ports that can support USB3.1 gen2.

An example of a "put together" drive would be a Samsung t7.

Or, you could buy the "nvme blade" SSD of your choice, and put it into a USB3.1 gen2 enclosure. There are many available and many just snap together.

You didn't tell us which version of the OS you're using.
If it's Mojave or later, erase the drive to APFS, GUID partition format.

Then use either CarbonCopyCloner or SuperDuper to "clone over" the contents of the fusion drive to the SSD. SD is a little easier for a first-time user. BOTH are free to download and use for 30 days, so doing this will cost you nothing.

Set up this way, a USB3.1 gen2 external boot drive should give you read speeds of about 800MBps or even better.

Adding RAM will help, too, but speed-wise, the biggest change you can make is to go to a "Full SSD" boot drive...

 

[wilberforce]

You DO WANT a USB3.1 gen2 SSD, which is almost twice as fast. The 2017 was the first iMac to have USBc ports that can support USB3.1 gen2.

An example of a "put together" drive would be a Samsung t7.

Or, you could buy the "nvme blade" SSD of your choice, and put it into a USB3.1 gen2 enclosure. There are many available and many just snap together.

2017 iMac supports TB3, which would be even faster, hence my posts #3 and #5 above.

 

[ufgatorvet]

I am on MacOS 12.5.1.

I do have a Time Machine that is a Synology disc. So is this what is occupying the Fusion drive space then?

I will investigate the above suggestions. I can't afford a Mac Studio and do not want the new(er) 24" iMacs so want to milk this desktop as far into the future as possible. ...

 

[wilberforce]

I am on MacOS 12.5.1.

I do have a Time Machine that is a Synology disc. So is this what is occupying the Fusion drive space then?

I don’t really know, but it is one possibility. I gave you a method to find and delete the snapshots, you can see if this helps. Also I suggest clear your downloads folder and empty your trash, and use the ”Manage…” button.
You can also see hidden files in Finder by Cmd+Shift+Period. (Repeat this to hide again.) Don’t delete any hidden files, as they are hidden for a reason.
btw, snapshots are provided because they are useful. Much quicker to retrieve a file from a snapshot than from the external TM drive. The system will purge snapshots if space is needed for something else.