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RAM usage questions

apple fan23

apple fan23

macrumors regular
Original poster
Mar 9, 2022
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I am trying to figure out how much RAM I use, by looking at the activity monitor. I am on an i7 32GB MacBook. The activity monitor tells me I am using 20gb of ram and 14gb of app memory right now (and most of the time). There is no swap and pressure is green. As I am already at 14gb of app memory, and have not opened any bigger applications yet, so surely this tells me, that for my next MacBook I should stick to 32gb?!
Yet, everywhere on the internet I hear that unless you do video or photo editing you don't need so much ram and 16gb is absolutely fine for the average user.
I don't do any photo or video editing. My usage is (I imagine) fairly normal. Programs open right now: Safari (4 tabs, incl. me writing this post), Mail, Calendar, Outlook, Notion, messages, Photos. Nothing too weird about that, right? And yet it tells me I would struggle with 16gb? I haven't even opened some ram hungry apps yet like Music, Whatsapp, Zotero, Word, Scrivener etc etc. None of those programs are outside normal usage. Yet, I feel like I should stick to 32gb. So am I not the average user then?
Any advice would be appreciated.
 
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It certainly seems like 16gb would be enough.

Remember that an OS will use as much RAM as it can practically do so.

So while you’re showing as 20 in use with green memory pressure. Running a 16gb system you may show 10 in use and a green memory pressure with the same apps.
 
Thanks. When I open some more programs for work (PDF's, Zotero), I go up to 23gb/16gb, still no swap or pressure.
 
apple fan23 said:
Yet, everywhere on the internet I hear that unless you do video or photo editing you don't need so much ram and 16gb is absolutely fine for the average user.
Click to expand...
Don't believe everything on the internet.
Nobody on the internet knows what YOU use.
If you are currently using 20gb (more than 16), ok an Apple Silicon Mac will still handle it, but you will have a lot more disk swaps and yellow memory pressure.

My rule is never get a new computer with less ram than previous.
It will always feel like a downgrade, even though the computer is much newer/better spec.

You really cannot have too much ram.....;)
 
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MarkC426 said:
Don't believe everything on the internet.
Nobody on the internet knows what YOU use.
If you are currently using 20gb (more than 16), ok an Apple Silicon Mac will still handle it, but you will have a lot more disk swaps and yellow memory pressure.

My rule is never get a new computer with less ram than previous.
It will always feel like a downgrade, even though the computer is much newer/better spec.

You really cannot have too much ram.....;)
Click to expand...
This is just false. Using more than 16gb does not mean you will have issues with only 16gb total.

The OS will take as much as it can. Even if it’s not necessary
 
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apple fan23 said:
I am trying to figure out how much RAM I use, by looking at the activity monitor. I am on an i7 32GB MacBook. The activity monitor tells me I am using 20gb of ram and 14gb of app memory right now (and most of the time). There is no swap and pressure is green. As I am already at 14gb of app memory, and have not opened any bigger applications yet, so surely this tells me, that for my next MacBook I should stick to 32gb?!
Yet, everywhere on the internet I hear that unless you do video or photo editing you don't need so much ram and 16gb is absolutely fine for the average user.
I don't do any photo or video editing. My usage is (I imagine) fairly normal. Programs open right now: Safari (4 tabs, incl. me writing this post), Mail, Calendar, Outlook, Notion, messages, Photos. Nothing too weird about that, right? And yet it tells me I would struggle with 16gb? I haven't even opened some ram hungry apps yet like Music, Whatsapp, Zotero, Word, Scrivener etc etc. None of those programs are outside normal usage. Yet, I feel like I should stick to 32gb. So am I not the average user then?
Any advice would be appreciated.
Click to expand...
Can you post a screenshot of the Activity Monitor. I do believe you, but the last thing you should do is go from 32GB of RAM to 16GB.
 
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I went from 40 GB in a 2017 iMac to 32 GB in Windows to a 16 GB Macbook Pro. I haven't regretted the downsizing. I was using 8 GB in Windows for many years prior to the iMac. 32 GB is inexpensive excess with standard DIMMs. 16 GB is fairly expensive excess from Apple.
 
Thanks everyone! here is a screen shot from just now. Surely fairly 'average' usage yet still using nearly 23gb of Ram. Screenshot 2022-06-12 at 08.52.39.png
 
It's nice seeing 0 swap....most M1 machines don't show this (as people under spec ram them).

Funny thing is on the main MacRumors page today, 10 years ago the first retina mbp was released which supported 16gb ram (and that was 10 years ago).
 
It seems that your usage is pretty normal and 16GB would handle it fine. The high RAM usage is an inherent feature of macOS's memory management system which I attempt to describe below, do correct me if I am wrong.

macOS (whose kernel is derived from Mach kernel) features "a fully integrated virtual memory system" that is always on. The virtual memory system comprises the physical RAM itself (the expensive ones) and drive storage (also expensive but much cheaper). The memory paging scheme maximises system performance by looking at app profiles and memory usage pattern, then preemptively loads pages (memory blocks) which the apps might use. This usage pattern can be built up over time as you use the app, or the app developers can specify it.

The paging system is configured such that it loads and retains pages in memory. Pages that are recently accessed are marked as active, otherwise they become inactive. When more memory is required by apps and there are no longer free memory, inactive pages are removed to make way for new active ones. The removal can be a complete purge, or they may be compressed or swapped. The exception is wired memory which is required by the kernel and its data structure, and cannot be paged out. This arrangement maximises system performance since loading data into memory takes much longer than paging existing ones in memory. Hence the adage "unused memory is wasted memory".

The memory pressure chart in Activity Monitor is the summary of the above interactions. Activity Monitor can indicate "high memory usage" but low on memory pressure, simply because of the qualities described above. Memory pressure turns yellow or red when macOS cannot efficiently use memory (because of high swap/compression-decompression caused by lack of RAM).

I was looking into this to understand my own use case. I use R/Python to wrangle data for data science purposes, which can run into hundreds of GBs. That surely overwhelms the 64GB of RAM on my M1 Max isn't it? However, the operations run fine (just takes a while). This is because most of the data stays on the disk and only a portion of them are operated upon by R (hence marked as active) at any one time. Nonetheless if I look at Activity Monitor, it will indicate R memory usage as 200+GB, but the memory pressure is yellow. It is also interesting to see the spikes in memory pressure into red as certain calculations are being performed, or lookups being matched, so understanding this helps in code optimisation exercises - e.g. deciding when to chunk datasets/operations or use RDBMS's. After the script runs successfully, memory usage will remain high even after explicit object removal and garbage collection commands (i.e. tell R/macOS that the pages are no longer required). When other apps request for pages, R's memory usage will go down as macOS purges the inactive memory to make way for other apps.

Hope that helps!
 
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Screenshot 2022-06-12 at 7.06.38 PM.png

What happens when I push the system to the limit: In this case all 64GB of RAM is fully utilised with swap also filling up. (I can actually see the free disk space dropping by 70+GB, and the P cores were not running at 100% because of increased swapping.) Activity Monitor shows yellow memory pressure and about to turn red. Having said that, it takes quite a bit to push the system this far. (Side note: Will M2 Max be equipped with 96GB of RAM?)

Understanding how your apps use memory is definitely helpful in deciding how much RAM to spec out. If your apps need to hold a large amount of data/objects in memory for active paging, then it is definitely advisable to spec out as much RAM as necessary. If this is not the case (or if you have a lot of apps open, but the memory can be swapped), then it is fine to have a lower RAM capacity. If you are not sure, you can perhaps throw a bunch of demanding tasks at your MBP, and see how the memory pressure in Activity Monitor goes.
 
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apple fan23 said:
Thanks everyone! here is a screen shot from just now. Surely fairly 'average' usage yet still using nearly 23gb of Ram.View attachment 2018017
Click to expand...
I would highly suggest you stick to the highest memory configuration you can. Actively used memory is already near the 24GB mark.

If you can stay at 32GB, if you can't try to get 24GB at minimum.
 
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ram is expensive but it's probably worth it... :(
Thank you for the interesting discussion. Perhaps I am not an 'average user' after all LOL. Perhaps my next MacBook should be the 14" M1pro 32gb.... pricey, but hopefully should last for a good few years+.
 
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there's just the 2 month waiting time and the question to buy now or wait for M2Pro?
 
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