Memory swap usage higher on M1 chips than intel

[Kraizelburg]

Hi all, I have noticed that the M1 chip uses a lot of swap memory no matter what you do. Just a few safari tabs open seems to trigger swap memory to a few hundreds meanwhile in intel was at 0 all the time unless I pushed really hard.

I wonder if someone else has noticed this behavior too?

 

[Frixos]

Hi all, I have noticed that the M1 chip uses a lot of swap memory no matter what you do. Just a few safari tabs open seems to trigger swap memory to a few hundreds meanwhile in intel was at 0 all the time unless I pushed really hard.

I wonder if someone else has noticed this behavior too?

I'm on an Intel (2013 MBP, 16GB; Catalina), and I notice it using anywhere from a few hundred MB to a GB of swap with casual use (with several GB of RAM unused).

 

[Kraizelburg]

I'm on an Intel (2013 MBP, 16GB; Catalina), and I notice it using anywhere from a few hundred MB to a GB of swap with casual use (with several GB of RAM unused).

I meant only with just a few safari tabs open, maybe 1 video playing on youtube, gmail and some other. The same setup causes more swap memory usage in my M1 macbook air.

I think the way that the new M1 handles memory is totally different and places more data in swap than intel, maybe it's something intrinsic to ARM, I don't know.

 

[_Forever]

I keep seeing this about memory swap, is this a big deal? I would imagine the RAM is faster than the SSD but is that the only negative?

 

[UBS28]

You don’t want swap memory with SSD’s and flash storage because it will kill it in the end.

 

[Kraizelburg]

You don’t want swap memory with SSD’s and flash storage because it will kill it in the end.

I am not an engineer but I think iPhones work exactly the same way and that's why they have less RAM than android, and iPhones have flash storage too.

 

[AlexOnBoard]

Mine swap used 11GB, have a look: https://forums.macrumors.com/thread...10-hours.2271835/?post=29315611#post-29315611

 

[Frixos]

I meant only with just a few safari tabs open, maybe 1 video playing on youtube, gmail and some other. The same setup causes more swap memory usage in my M1 macbook air.

I think the way that the new M1 handles memory is totally different and places more data in swap than intel, maybe it's something intrinsic to ARM, I don't know.

Yes, that's the kind of usage that results in swap usage on my Intel MBP.

You don’t want swap memory with SSD’s and flash storage because it will kill it in the end.

That's not an entirely accurate statement. Swap memory is normal on macs. A few GB of swap memory is not gonna kill your SSD anytime soon. If you find yourself swapping 1TB, sure that'll kill it off.

 

[DeanL]

I'm not sure why people have a fixation on this.
This isn't 2012. SSDs have evolved. Swap usage won't kill a SSD. It's part of the functioning of the computer.

 

[bill-p]

I am not an engineer but I think iPhones work exactly the same way and that's why they have less RAM than android, and iPhones have flash storage too.

Well, iPhones don't work the same way at all. iOS will simply just kill your app if it doesn't have enough memory, and... all iOS apps are designed with very aggressive memory management in mind.

The fundamental difference between iOS and MacOS in this case is that iOS does not write to storage when memory runs out, but MacOS does.

And writing too many times to the flash storage kills it.

SSD Lifespan: How Long do SSDs Really Last?

Ontrack discusses SSDs, physical faults, malfunctioning controller and storage chips, and hazards of recovering data with data recovery software.

www.ontrack.com

This article explains it pretty well. Most manufacturers now rate their SSDs at around 150TB written before they don't warrant it anymore. So you need to write about 410GB/day for the SSD to get into "no guarantee" zone, or about 100GB/day for 4 years straight.

If you're using swap any less than that, your drive should last up to 4 years at least. Heck, if you're constantly writing 10GB daily, the drive will last 40 years before it hits the "no guarantee" zone. Imagine that...

So even though it is a concern, I don't think it's a realistic concern in 2020. Just use the computer as is if hitting swap doesn't cause it to slow down.

 

[ArPe]

It doesn’t ‘kill’ SSDs, it just degrades performance over time depending on how big your data and swaps are. The more full your drive is the less well it performs too.

In a decade when all ram, video memory and storage become a giant unified high performance pool a new type of highly durable memory format will be around.

 

[hugodrax]

I'm not sure why people have a fixation on this.
This isn't 2012. SSDs have evolved. Swap usage won't kill a SSD. It's part of the functioning of the computer.

my mac mini from 2012 with SSD/fusion drive lasted 8 years an still running with zero issues. I think the SSD lifespan fear is way overblown at this stage,.

 

[ArPe]

my mac mini from 2012 with SSD/fusion drive lasted 8 years an still running with zero issues. I think the SSD lifespan fear is way overblown at this stage,.

Lifespan and performance not the same thing ? everything natural or unnatural degrades with usage.

 

[LFC2020]

Stress less, use your machine the way it's meant to be used and enjoy it.

 

[DeanL]

Lifespan and performance not the same thing ? everything natural or unnatural degrades with usage.

Except someone up there talked about “killing” the SSD, not merely degrading it.

 

[MrEcted]

Apple has some of the best engineers on the planet who know what they are doing. Swap memory shouldn't carry the same negative implications that it did in the past when hard drives were super slow. Furthermore, about SSD degradation, while it is true, modern SSDs handle hundreds of terabytes of write cycles before they degrade and modern algorithms are smart enough to spread it out so the same memory cells aren't being hammered over and over again. This does mean that as your SSD fills up it will become more constricted, but it's nothing to worry about, especially if you plan on upgrading to a new computer in the next 10-15 years.

I run a Linux database server with a really really old 64GB SSD that is over 10 years old at this point, that mini server is constantly resorting to swap but it's still ticking along just fine.

For a VAST majority of people this won't matter and your SSD, despite having known degradation issues after MANY write cycles, will likely outlive almost any platter drive from the past.

 

[leman]

Swapping is an essential part of modern virtual memory management. M1 machines have excellent performance, I am sure that Apple has finetuned the hell out if it. I wouldn’t worry about this.

You don’t want swap memory with SSD’s and flash storage because it will kill it in the end.

Concerns about SSD endurance might have been valid 6 years ago, but we are long past them.

 

[IowaLynn]

Good interview about memory.

Why Are The Memory Options So Limited on Apple's New M1 Macs?

The title of this post raises an interesting question. There has been some chatter from people complaining that the new M1 Macs from Apple have lower memory options available than their Intel counterparts. But I have also seen folks say that perhaps memory works differently or is more efficient...

eshop.macsales.com

 

[UBS28]

Swapping is an essential part of modern virtual memory management. M1 machines have excellent performance, I am sure that Apple has finetuned the hell out if it. I wouldn’t worry about this.




Concerns about SSD endurance might have been valid 6 years ago, but we are long past them.

Having no swap memory is better than having swap memory. That is what your RAM is for, not your SSD.

Also swap memory is not a workable solution as you will get out of memory errors.

 

[UBS28]

Good interview about memory.

Why Are The Memory Options So Limited on Apple's New M1 Macs?

The title of this post raises an interesting question. There has been some chatter from people complaining that the new M1 Macs from Apple have lower memory options available than their Intel counterparts. But I have also seen folks say that perhaps memory works differently or is more efficient...

eshop.macsales.com

On youtube some people opened the inside of the Mac Mini and it is a very small package. So given the limited space Apple had to work it, it is likely that there was no space to put more memory in.

If Apple creates a larger integrated chip (with GPU, RAM, SSD and CPU on 1 die), then there is more space to fit in more RAM. The Mac Mini can certaintly include something alot bigger as it looked quite empty inside. So I think it will get an other update next year with a bigger M1X maybe.

The larger M1X, M1X Pro or whatever name Apple will choice, will most likely be able to fit more RAM in there as it has more room to work with.

It is probably also the reason why such limited amount of ports are available with the M1, because it is a very small package.

 

[Frixos]

Having no swap memory is better than having swap memory. That is what your RAM is for, not your SSD.

Also swap memory is not a workable solution as you will get out of memory errors.

It appears you don’t understand. MacOS uses swap even if you have several GBs of unused RAM.

 

[Kraizelburg]

It appears you don’t understand. MacOS uses swap even if you have several GBs of unused RAM.

That's my point, Big Sur on M1 chips behave different than on x86 chip, it's more like an iPhone than an intel PC.

 

[UBS28]

It appears you don’t understand. MacOS uses swap even if you have several GBs of unused RAM.

It appears you don’t understand how computers work as some my projects literally do not run with 16 GB of RAM even. I get out of memory errors.

It is fine that you will skimp on memory, but I certaintly will buy the optimal amount of RAM that is required. And that means waiting for the models next year which will have higher end options.

 

[Sanpete]

Having no swap memory is better than having swap memory. That is what your RAM is for, not your SSD.

Better if you don't consider cost and wattage.

 

[name99]

Hi all, I have noticed that the M1 chip uses a lot of swap memory no matter what you do. Just a few safari tabs open seems to trigger swap memory to a few hundreds meanwhile in intel was at 0 all the time unless I pushed really hard.

I wonder if someone else has noticed this behavior too?

Before we get worked about this, what exactly are you reporting and do you understand the numbers?
The amount of VIRTUAL address space used means nothing.
The amount of PHYSICAL memory used means very little. By design every OS will hold as much as it can in RAM (up to including parts of files that were opened some time ago) on the off chance that they'll be re-used.

The only number that really matters is the number of WRITES to flash from the memory system, and I'm not sure you can trivially get at that number. In theory this should be the pageOuts/s number, but it is possible that
- Darwin reports the compression of pages as pageouts (but such pages do not go to flash of course)
- Apple Silicon uses a different algorithm for page compression (likely hardware accelerated), and so is willing to be more aggressive about page compression.