Explain RAM Utilization on macOs

[mglakner]

I use a 2014 mac mini as a home server (plex, itunes, photos, etc.) it has 8gb of Ram. I run some ram intensive apps like a Ubiquiti controller and my usage was into the 60-70% range, so i thought i needed more ram, so i bought a 2012 mac mini with 16gb. I cloned my 2014 to my 2012 and booted both up, let them run for a few hours and to my surprise both are hovering Ram usage at 65%, how is this possible and why? I attached screenshots of the usage. I can confirm these are clones of each other, running the same apps and versions. Can someone help me understand:

1. what the RAM is doing?
2. If 8gb and 16gb both run at the same usage then is Ram not my issue?
3. How can the same systems run one at 10gb usage and one at 5gb usage when they're the same.

Heres the 2012 (16Gb ram usage)

Heres the 2014 (8Gb ram usage)

 

[chown33]

MacOS will cache things to whatever extent free (unused) memory allows. In other words, if RAM isn't being used for any other purpose, the OS will use some of it as cache.

The paging/swapping system also participates in this. Memory is compressed or left uncompressed depending on how much unused RAM there is. Compressing and decompressing consumes computing resources, but it's less resources than swapping. Of course, leaving things uncompressed is even less resource-intensive.

 

[Collywobbles]

perhaps this is a question you should put to bjango software as the image is from iStatMenus.
but here is a couple of (old) articles found with a quick 'duck duck go'...

What Is Wired Memory and How to Free Up Memory on Mac

While reading thru some Apple forums, I found a question people asked a lot. While most responses were generally correct, I felt that all answers lacked some important details and

macmyths.com

What is free, wired, active, and inactive system memory (RAM)? | MacYourself

Mac users: Have you ever wondered what all that system memory stuff in the Activity Monitor was all about? Understanding the terminology – free, wired, active, and inactive RAM – can help you decide if your Mac has enough memory. A quick...

www.macyourself.com

 

[Collywobbles]

I should add, I run a ubiquity controller on a PI, it's prone to breaking and I really don't want to break my Mac.. You'll have gods only game trying to remove it. A Ubiquiti controller is not RAM intensive if it runs ok on a 1GB ram PI3. Consider this, a 32gb MacBook Pro 16". RAM is treated like a file in unix, you'l continue to use it till you run out. A element of "garbage collection" eventually occurs if the OS thinks you're not going to use something again or it needs the "space".

 

[MacCheetah3]

Here are brief explanations of each type of use:

View memory usage in Activity Monitor on Mac

In Activity Monitor, view the amount of system memory being used on your Mac, including physical, compressed, wired, and app memory.

support.apple.com

Basically, if the system isn't creating swap files the physical RAM amount is good.

 

[nickdalzell1]

It's a UNIX thing "Unused RAM is wasted RAM"

Why It's Good That Your Computer's RAM Is Full

Is Windows, Linux, Android, or another operating system using a lot of RAM? Don’t panic! Modern operating systems use RAM as a file cache to speed things up.

www.howtogeek.com

 

[mglakner]

Thank you all for the replies. So im understanding this write, i only need as much RAM as my most RAM intensive apps is using and the rest is just filtered through as needed.

So then do i need 16Gb of ram or is 8Gb enough if its a file server running monitoring software mostly?

 

[MacCheetah3]

I am indeed a bit confused by the App Memory usage difference because you said "I cloned my 2014 to my 2012 and booted both up, let them run for a few hours" and by cloned I assume you mean OS as well. Nevertheless, the 8GB equipped 2014 Mac mini did report nearly 3GB free, i.e. unused. Therefore, it would seem that 8GB is sufficient for your uses.

 

[mglakner]

I am indeed a bit confused by the App Memory usage difference because you said "I cloned my 2014 to my 2012 and booted both up, let them run for a few hours" and by cloned I assume you mean OS as well. Nevertheless, the 8GB equipped 2014 Mac mini did report nearly 3GB free, i.e. unused. Therefore, it would seem that 8GB is sufficient for your uses.

Thank you for that information. Yes i just cloned the 2014 8gb drive to the 2012 16gb drive and started both up, connected to ethernet and accessed remotely on my macbook and let them run.

My theory was if i upgraded the 16gb was going to be way under usage, but i was wrong, so i turned to you guys.

I appreciate your help, and i would welcome anyone else's opinions.