High Sierra - Excessive RAM usage ?

[dogslobber]

I don’t mean this with any offense but I don’t have a better way to word it: your understanding of RAM management harkens to the days prior to 10.8.

Sandboxing was introduced in 10.7 which is when the memory footprint of OS X ballooned. It means that every app which opens a new instance of itself generally does so as a separate process. Previous to this the new instance would share the loaded libraries of the initial instance. The biggest impact to this was web browsers. Each new tab is like running a new Safari app by itself. That's the price of security: more memory.

To mitigate, Apple did introduce compressed memory pages in Mavericks which occurs before swap is used. But while it helps, it can't prevent OS X memory leaks. They're just compressed now.
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Hello guys,

I've finally upgraded my 2016 TB MacBook Pro to High Sierra 10.13.1 by doing a clean install. I have no issues and performance seems to be on par - or slightly better - with Sierra but I've noticed that lots of RAM is active. At the moment, I have only iMessage, Safari and Mail open and that has 8.58GB RAM active. Is that normal ? Have you noticed anything similar ? Thank you in advance !

I find that just booting High Sierra on my 4GB MBA 2010 has it swapping already. I'd say the minimum footprint for OS X is 8GB possibly 16GB nowadays. Compressed memory and SSD swapping help mitigate the slowness but you still take a hit for low RAM systems running HS and it causes the system to feel sluggish.

 

[arefbe]

BTW, do you mean 2015 MacBook Pro? You can’t configure the 2015 MacBook with 16 GB RAM.

Yes, the MacBook Pro. My bad!

 

[EugW]

I find that just booting High Sierra on my 4GB MBA 2010 has it swapping already. I'd say the minimum footprint for OS X is 8GB possibly 16GB nowadays. Compressed memory and SSD swapping help mitigate the slowness but you still take a hit for low RAM systems running HS and it causes the system to feel sluggish.

Do you have a lot of extra services launched at boot up? I agree that 4 GB is limiting, but my experience wasn't quite that bad.

Mind you, my 4 GB machine was a secondary machine. My primary machines (16 GB MacBook and 24 GB iMac) have more stuff installed.

Mainly Safari, Mail, Terminal, and Pages (yes, not built-in, but still Apple-developed). It does swap, but there is no noticeable performance hit. I quit applications completely when I'm done with them, so they do not stay open in the background, which helps to some extent.

Yeah, that would help a lot.

 

[bizzwriter]

I'm curious. Do you people with 12-48gb of RAM. Do you see a Swap Used on your machines? I have 16gb in my 2015 MacBook with no more than Safari, with 2 tabs, iTunes, Pages and Messages open, and I see that Swap has been used. Should that be?

I have 48GB of RAM and my machine is ALWAYS at 0 bytes swap used. My typical usage is Mail, iMessage, iTunes, Chrome with 10 tabs open, Google Drive, an Excel spreadsheet open, a Word file open. Just checked, and I have 16KB (yes, that's KB) of compressed memory going right now.

 

[geoenviro]

Thank you for your answer. I'm no computer expert - I admit that - but if everything is OK then I'm happy with that.

I'm not so sure everything is ok. I just installed High Sierra yesterday and after freeing up my RAM I am sitting here watching it drop from 12.94 to 9.54 bit by bit over the past 5 minutes. I became aware of the problem when during routine maintenance I found my memory had fallen to 1000MB and understandably became concerened. I am running a Mid 2012 15-inch Macbook Pro with an SSD with 450.3GB free and 749.95GB used/2.6GHz Intel Core i7/16GB RAM/1600MHz DDR3. Since I have typed this my RAM has dropped to 9.1. I have been using Macs since 1988. I don't think this is normal. Anyone have any suggestions to stop the bleeding?

 

[dogslobber]

There should always be a large pool of free unused memory.

 

[simonsi]

There should always be a large pool of free unused memory.

Why? So you can claim how much RAM is being wasted by the system?

macOS has better RAM management than that. There <should> be a clear option for the OS to free up memory if needed, macOS does just that, until then keeping a closed app in RAM (for example), is potentially very good for the user experience if that app is needed again and the system has no better use for the RAM otherwise.

 

[dogslobber]

Why? So you can claim how much RAM is being wasted by the system?

So you don’t need to wait to do work.

 

[simonsi]

Reread my explanation, macOS doesn't need a constant large pool of unused memory to achieve that.

It takes zero additional time to write over memory that has a previously used but closed app in it vs "empty" RAM. "Free" and "unused" RAM is a legacy from 5yrs ago that neither macOS or Windows now use. RAM is simply overwritten, not zeroed out before use.

macOS simply keeps track of which memory it is free to use and which has active apps/os in it.

 

[dogslobber]

Reread my explanation, macOS doesn't need a constant large pool of unused memory to achieve that.

I don't need to re-read anything you wrote as I know precisely how VM works. What you are struggling to describe is called the file cache. When a process goes through the fork/exec step in the kernel, then the kernel will free up memory from the file cache and load the program and libraries from disk into that memory space.

 

[EdwardC]

I had a similar experience on my late 2013 iMac with only mail open I was showing over 4 gigs of RAM usage. After a few issues I ended up taking it to the Genius Bar and had the drive wiped and Sierra installed. Much better now.

 

[simonsi]

I don't need to re-read anything you wrote as I know precisely how VM works. What you are struggling to describe is called the file cache. When a process goes through the fork/exec step in the kernel, then the kernel will free up memory from the file cache and load the program and libraries from disk into that memory space.

Cool - so you should have understood my original explanation then:

...the OS to free up memory if needed, macOS does just that, until then keeping a closed app in RAM (for example), is potentially very good for the user experience if that app is needed again and the system has no better use for the RAM otherwise.

Oh and the above has zero to do with virtual memory and everything to do with memory management of real memory.

 

[dogslobber]

Oh and the above has zero to do with virtual memory and everything to do with memory management of real memory.

Please go educate yourself about VM. I’d suggest starting with the elementary descriptions on Wikipedia. Then try a good college text on the subject for in-depth coverage.

 

[Retromac2008]

please be nice

 

[simonsi]

Please go educate yourself about VM. I’d suggest starting with the elementary descriptions on Wikipedia. Then try a good college text on the subject for in-depth coverage.

Your original statement was wrong, you clearly dont like being told so. Feel free to make any assumptions you like about my knowledge of vm or anything else, it doesnt make your original statement any more correct.

 

[h9826790]

I'm curious. Do you people with 12-48gb of RAM. Do you see a Swap Used on your machines? I have 16gb in my 2015 MacBook with no more than Safari, with 2 tabs, iTunes, Pages and Messages open, and I see that Swap has been used. Should that be?

I have 48GB RAM, and no matter how I stress my Mac, always zero SWAP. Obviously HS change the memory management a bit, in Sierra, I often see up to around 5GB SWAP usage (of course, only under high workload)

 

[arefbe]

I have 48GB RAM, and no matter how I stress my Mac, always zero SWAP. Obviously HS change the memory management a bit, in Sierra, I often see up to around 5GB SWAP usage (of course, only under high workload)

That's good to know. I forgot to mention that I am still on Sierra. If High Sierra manages memory better, maybe it's time to upgrade. Thanks.

 

[Tarek]

I just updated to Mac OS High Sierra today and I am enjoying it so far. I feel like my computer's performance has definitely improved quite a lot. I just checked Activity Monitor and it says that 6.25 GB of memory is being used out of 8 GB, and I honestly have no idea if that's normal or high, but I'm guessing it's the former because the performance is quite excellent. I only have Google Chrome opened but with a lot of tabs (11), one of which is a live video stream.

 

[andygoode]

Hi Y Mac Pro 5.1 works fine with 64 gb of memory ,yet I added another 64 gb.
And my computer will not start it just goes round in circulas and seems to keep trying to start yet not actually happening.
if I take my old memory out it see the 64 gb of new memory. If take out the new memory its the old memory but will not let me use all 8 slots for some reason,all the memory is ecc .16 gb a stick

 

[jerwin]

Hi Y Mac Pro 5.1 works fine with 64 gb of memory ,yet I added another 64 gb.
And my computer will not start it just goes round in circulas and seems to keep trying to start yet not actually happening

This is a zombie thread, and you're scaring the 4GB crowd.

How much memory can you add before it starts crashing?

also, this may be of interest

https://forums.macrumors.com/threads/mac-pro-cpu-compatibility-list.1954766/

 

[andygoode]

Anything over 64 gb and it will not work . And it just does not want to know.
Andy

 

[Yahooligan]

Anything over 64 gb and it will not work . And it just does not want to know.
Andy

Please start a new thread instead of hijacking an old, unrelated thread.

Have you tried with 96GB installed (6 DIMMs) and see if that works? Also, you didn't mention your 5,1 specs and you don't have any info in your signature to help folks know what your 5,1 setup is.

 

[simonsi]

Anything over 64 gb and it will not work . And it just does not want to know.
Andy

Sounds like the RAM you are fitting is incompatible (or just significantly different in actual performance), by enough margin to cause a problem.

If you remove the old 64GB and fit the new 64GB in place does it boot normally?

 

[h9826790]

Hi Y Mac Pro 5.1 works fine with 64 gb of memory ,yet I added another 64 gb.
And my computer will not start it just goes round in circulas and seems to keep trying to start yet not actually happening.
if I take my old memory out it see the 64 gb of new memory. If take out the new memory its the old memory but will not let me use all 8 slots for some reason,all the memory is ecc .16 gb a stick

Your info in this post is contradict to your post in the Mac Pro forum.

Are you using 32GB DIMM or 16GB DIMM?

And what’s the detail DIMM spec? You never answer that in the Mac Pro forum, but suddenly ask the same question here with different info.

Again, without knowing ALL your DIMM detail spec, it’s hard to tell why they won’t work

 

[andygoode]

Please start a new thread instead of hijacking an old, unrelated thread.

Have you tried with 96GB installed (6 DIMMs) and see if that works? Also, you didn't mention your 5,1 specs and you don't have any info in your signature to help folks know what your 5,1 setup is.

Hi I have tried every combination possible and any thing over the original 64 gb I had in the machine will not work I have tock out my old ram replaced it with 64 gb of new ram and it works but when you go over 64 gb it stopes. my machine is 6core chips 3.46
GHZ5.1 Mac Pro desktop