RAM usage question

[Spectrum]

I'm currently doing some data crunching in R on a 6-core i7 Mac mini 32GB RAM: 6 threads running, and RAM usage looks like this:

My question is: Am I really using 26 GB of RAM? Or only 4GB? (The 'Wired Memory'). Pressure is green (whatever that means?)

The question is pertinent to this forum because I am wondering whether I may need a 2020 13 inch MBPro with 16 GB or 32 GB.

Cheers for any insight anyone has!

 

[jerwin]

The question is pertinent to this forum because I am wondering whether I may need a 2020 13 inch MBPro with 16 GB or 32 GB.

stop your program, format a 16 GB RAM Disk. and see if your program runs more slowly. It's probably not neccessary to fill the ram disk with random, uncompressible data, merely formatting it will reduce available ram.

https://blog.macsales.com/46348-how-to-create-and-use-a-ram-disk-with-your-mac-warnings-included/

 

[ctjack]

My question is: Am I really using 26 GB of RAM? Or only 4GB? (The 'Wired Memory'). Pressure is green (whatever that means?)

You are using 22Gb of RAM (18.2 gb(R) + 4 gb(Mac OS itself)). So you have free 10GB of Ram.

The question is pertinent to this forum because I am wondering whether I may need a 2020 13 inch MBPro with 16 GB or 32 GB.

That things needs real world tests from you on the same project on 2 different laptops with 16gb and 32gb of RAM.
Because the fact that R used 18GB of Ram doesn't mean that it needs it or uses it for work.
Because sometimes software are doing a lot of bloatware in RAM, while it can eat less.
For example one man from youtube made a video about his new MBP 13 2020 with 32GB of RAM: his lightroom was using 20+ GB of RAM for photo editing. While my lightroom operated really good on 100 RAW photos with only 5GB of RAM used. So you have to test the water.

 

[jerwin]

Wired memory is memory that can't be allocated to userland programs paged out. The kernel, drivers, and the shared VRAM occupy wired memory.

see also:

https://wiki.freebsd.org/Memory

 

[Appledoesnotlisten]

Guys, I have a similar question.
My Radeon 560 memory is maxed out and SWAP memory started to max out as well, but RAM remains around 75%.
Will I benefit if I go from 16Gb to 32 Gb?

 

[||\||]

I'm currently doing some data crunching in R on a 6-core i7 Mac mini 32GB RAM: 6 threads running, and RAM usage looks like this:
View attachment 937472
View attachment 937473

My question is: Am I really using 26 GB of RAM? Or only 4GB? (The 'Wired Memory'). Pressure is green (whatever that means?)

The question is pertinent to this forum because I am wondering whether I may need a 2020 13 inch MBPro with 16 GB or 32 GB.

Cheers for any insight anyone has!

"Wired Memory" is best thought of as what the system is using. System processes, etc. Necessary for everything to run. The rest can be swapped out or compressed. You are using 26GB, but 22GB of it can be shuffled around. 4GB used by system processes is not bad. Mojave idles around 3GB for me.

 

[||\||]

Guys, I have a similar question.
My Radeon 560 memory is maxed out and SWAP memory started to max out as well, but RAM remains around 75%.
Will I benefit if I go from 16Gb to 32 Gb?
View attachment 939276View attachment 939277

I think it's more helpful to use Apple's own indicators. THey make it very easy and non-technical. What color is the memory pressure in Activity Monitor. If this is an extra ordinary workload, you are probably fine, as the system is at about 1/3 pressure. If you need to push it even more on the regular 32GB is worth considering. My guess is you do not. I have noticed that Mac OS will swap out data to disk it thinks it doesn't need even if it RAM resources still available.

 

[Appledoesnotlisten]

I think it's more helpful to use Apple's own indicators. THey make it very easy and non-technical. What color is the memory pressure in Activity Monitor. If this is an extra ordinary workload, you are probably fine, as the system is at about 1/3 pressure. If you need to push it even more on the regular 32GB is worth considering. My guess is you do not. I have noticed that Mac OS will swap out data to disk it thinks it doesn't need even if it RAM resources still available.

Apple memory pressure shows that there was a significant peak, but withing the green zone.
But the iStats menu said that ~100% of the swap was used.
What concerns me is that the computer got hooter and (I think) slightly slower when I kept so many windows/programs open.

This is a 2017 15" MBP though.
I hope that moving to the 16"/5600/16 will give me so much more resources with just 16Gb that I would not need 32Gb even if I did need it now.

 

[||\||]

Apple memory pressure shows that there was a significant peak, but withing the green zone.
But the iStats menu said that ~100% of the swap was used.
What concerns me is that the computer got hooter and (I think) slightly slower when I kept so many windows/programs open.

This is a 2017 15" MBP though.
I hope that moving to the 16"/5600/16 will give me so much more resources with just 16Gb that I would not need 32Gb even if I did need it now.

View attachment 939293

I don't know what the maximum size a swap file can be under Mac OS, but 3GB seems incredibly low. My understanding is that swap keeps increasing dynamically as necessary until the disk is full. You might not be getting accurate information from iStats. Activity Monitor tells you everything you need to know about RAM. Let the system do its thing from there. Green means you are good.

 

[Patcell]

Apple memory pressure shows that there was a significant peak, but withing the green zone.
But the iStats menu said that ~100% of the swap was used.
What concerns me is that the computer got hooter and (I think) slightly slower when I kept so many windows/programs open.

This is a 2017 15" MBP though.
I hope that moving to the 16"/5600/16 will give me so much more resources with just 16Gb that I would not need 32Gb even if I did need it now.

View attachment 939293

macOS assigns a certain amount of disc space for swap file - it changes based on what the system needs. iStat menus report the percentage of the swap file being used, which isn’t really helpful. For example, if macOS has 1GB assigned to swap and 1GB is being used, iStat shows 100% swap file used. That’s not helpful.

Also, macOS uses swap very liberally, so using swap file usage as an indicator of insufficient memory resources is not really a great idea. Unless there is a huge amount of disc space assigned to swap during a particular workload. In that case, macOS will report high (red) memory pressure in Activity Monitor.

macOS will use swap almost always when the computer is asleep (maybe to save power by not having to keep RAM powered??). My wife’s iMac with 64GB physical memory reports swap file usage after waking from sleep even with only a word processor open.

 

[avz]

macOS will use swap almost always when the computer is asleep (maybe to save power by not having to keep RAM powered??). My wife’s iMac with 64GB physical memory reports swap file usage after waking from sleep even with only a word processor open.

Thanks. I was wondering why upon waking from sleep the swap is always used even when 90% of available RAM is free. I guess it makes sense to shut down MacBook at night to prevent unnecessary writes to the SSD.
My unsupported MacBook5,1 with Mojave does not seem to do it(8GB of RAM installed) while my supported MacBookPro9,2 with Mojave does it(16GB of RAM installed).

 

[Patcell]

Thanks. I was wondering why upon waking from sleep the swap is always used even when 90% of available RAM is free. I guess it makes sense to shut down MacBook at night to prevent unnecessary writes to the SSD.
My unsupported MacBook5,1 with Mojave does not seem to do it(8GB of RAM installed) while my supported MacBookPro9,2 with Mojave does it(16GB of RAM installed).

That's interesting... are both machines on the same version of Mojave? Maybe a difference in hardware capabilities between the two... are they both using spinning hard disc drives? If the newer one is an SSD, maybe macOS will only page out to long-term storage if an SSD is installed to avoid a serious performance hit associated with spinning drives.

Just speculating... haha

 

[avz]

That's interesting... are both machines on the same version of Mojave? Maybe a difference in hardware capabilities between the two... are they both using spinning hard disc drives? If the newer one is an SSD, maybe macOS will only page out to long-term storage if an SSD is installed to avoid a serious performance hit associated with spinning drives.

Just speculating... haha

Yes, same Mojave version, both SSD's, FileVault both on. Maybe that's because I only recently upgraded from 4GB of RAM to 16GB and the system is still getting used to it? I will see how it plays in the future.