How important is 32gb of RAM?

UBS28

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If the 16gb RAM limit is exceeded, it can use the super fast SSD as RAM? (The SSD in the 2020 13” MBP can reach speeds of 3GB/s which should be fast enough to act as RAM I’d say).

Or is there really a big performance difference between 16 gb RAM (while using the SSD in situation when the RAM limit is exceeded) versus real 32 GB RAM?
 

KPOM

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Oct 23, 2010
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If the 16gb RAM limit is exceeded, it can use the super fast SSD as RAM? (The SSD in the 2020 13” MBP can reach speeds of 3GB/s which should be fast enough to act as RAM I’d say).

Or is there really a big performance difference between 16 gb RAM (while using the SSD in situation when the RAM limit is exceeded) versus real 32 GB RAM?
For the vast majority of users, 16GB is sufficient. Remember that Apple still sells Macs with 8GB of RAM, including the base MacBook Pro. 32GB is useful for running virtual machines, or RAM-intensive activities such as video editing.
 

UBS28

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For the vast majority of users, 16GB is sufficient. Remember that Apple still sells Macs with 8GB of RAM, including the base MacBook Pro. 32GB is useful for running virtual machines, or RAM-intensive activities such as video editing.
Yes, but I can exceed 16 gb of RAM once I start running VM’s. So I am wondering what the performance difference is between 32GB RAM and 16GB while making use of the SSD as temporary RAM.
 
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deeddawg

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Remember that 16gb of ram on a MacBook Pro works like this:

16GB
-1.5gb allocated for the GPU
-5 to 6 for the OS
so all you have that's usable for programs is about 9GB
I'm unsure where you're coming up with those numbers? macOS uses far less, and VRAM is typically dynamic, so it's not using the whole amount available unless needed in say a game or something.

Screen Shot 2020-05-21 at 9.33.36 AM.png


For the vast majority of users, 16GB is sufficient. Remember that Apple still sells Macs with 8GB of RAM, including the base MacBook Pro. 32GB is useful for running virtual machines, or RAM-intensive activities such as video editing.
For the vast majority, I'd say 8GB is sufficient. Then 16 for typical VM usage, or video editing, and 32 for when you're getting into several VMs going at a time.

I am wondering what the performance difference is between 32GB RAM and 16GB while making use of the SSD as temporary RAM.
That's dependent on how much swapping to disk you're doing, which depends on what's going on with the multiple VMs and how frequently you're moving between them. If you're switching once every ten or twenty minutes with the VM quiescent when inactive you'll see a different performance than if you're keeping four active VMs and switching between them every minute or two.

I will say that swapping to today's SSDs is a heck of a lot better experience than when a system would be thrashing swap on a slow HDD.
 

maflynn

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Or is there really a big performance difference between 16 gb RAM (while using the SSD in situation when the RAM limit is exceeded) versus real 32 GB RAM?
If you don't need it, then there's absolutely no impact on performance.
 
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ilikewhey

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I often touch 16gb with 20-30 chrome tabs open in 2 different windows. Along with ms words, safari, excel, vpn, and couple other gadgets. So I’ll probably get 32gb. Also ram ssd swapping will wear down the cells in ssd, given how the ssd is not even user replaceable anymore in Mac, I wouldn’t memory swap between ssd and ram on a regular basis
 

Howard2k

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Mar 10, 2016
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If the 16gb RAM limit is exceeded, it can use the super fast SSD as RAM? (The SSD in the 2020 13” MBP can reach speeds of 3GB/s which should be fast enough to act as RAM I’d say).

Or is there really a big performance difference between 16 gb RAM (while using the SSD in situation when the RAM limit is exceeded) versus real 32 GB RAM?

There is still a performance hit when you hit the ceiling. I have 8GB of RAM. MacOS is very good at memory management and while it certainly subscribes to the "the more RAM you have the more RAM I will use" approach, most people can likely get by with 8GB, even though a 16GB machine will show higher routine usage. I'd buy 16GB these days, but not because of any particular need.

Running with 8GB today I do occasionally see swapping from RAM to SSD. I usually don't notice it though, it's usually a background app being swapped to SSD while the foreground stuff stays in RAM. But certainly if I hammer it hard enough I will notice the swapping to SSD of a foreground app.
 

Fishrrman

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Feb 20, 2009
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Question:
"How important is 32gb of RAM?"

Answer:
It's only "important" if you NEED it.

DO you need it?
 
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pshufd

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Oct 24, 2013
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I'm currently on a 2008 Dell Desktop and it shows: 14.9 GB Committed and 16.9 GB Cached. So it's using system RAM as an SSD cache. I assume that macOS does something similar. All that extra RAM doesn't go to waste. My Mac only has 16 GB of RAM so I moved a bunch of applications to an old desktop.
 

Abaganov

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Jun 30, 2016
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I often touch 16gb with 20-30 chrome tabs open in 2 different windows. Along with ms words, safari, excel, vpn, and couple other gadgets. So I’ll probably get 32gb. Also ram ssd swapping will wear down the cells in ssd, given how the ssd is not even user replaceable anymore in Mac, I wouldn’t memory swap between ssd and ram on a regular basis
the OS will use as much as ram as you will give it, it could handle those 20 chrome tabs and other stuff probably ok with 8gb of ram as well
 
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cardsdoc

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I had the hardest time with this debate. It drove me crazy. On my 2012 retina 15" rMBP I maxed out ram to 16 GB knowing I could not upgrade later even though I did not need it at the time. I kept the computer longer than expected but the 16gb served me well and likely extended the lifespan for me (it still works fine). This is mostly for personal use and the most taxing things I would do is editing home made 4K videos, running a windows 10 vm with 8gb ram, and some video transcoding. I initially ordered a 2020 13" MBP with 10th gen i7/16GB/1TB. That's certainly fine for now and likely for years but I had a hard time wrapping my head around ordering the same amount of RAM as I did 8 years ago. I debated too long to cancel initial order before shipping and that unit came yesterday. But now I'm waiting on an "ultimate" config 2020 13" MBP with i7/32GB/2TB and will return the first one. Yes I know overkill and I may upgrade before RAM ever became limiting but financially it wasn't a big deal in the long run and I will just be more comfortable knowing it's a little more future proof for the unexpected. Resale may be better too. I do feel a little guilty for spending so much but that will fade. I wish RAM was still user upgradable like the good old days and Apple didn't charge insane prices though. If I recall my first MBP in 2007 came with 2GB and I then "maxed" it to 4GB on my own for a fraction of the Apple price.
 

Heelpir8

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Feb 13, 2019
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I like to imagine it's 2027 and I'm about ready to retire my 2020 MacBook Pro. What amount of RAM will likely be considered standard by then? Might having 32GB of RAM give me a year or three more of non-sluggish performance than 16GB would have? Even if I don't need that much right now? Maybe!
 

pshifrin

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Mar 14, 2010
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Question. Does the same app on a 16 vs a 32 machine consume the same amount of ram? i.e. if Chrome is open with 10 tabs and it consumes 4gb of ram on a 16, does it consume 4gb on a 32 with the same tabs or more because more is available?

I know the OS on a 32 uses more since it's available but do the individual apps? Considering the 16 vs 32 argument myself as the base upper tier 16/1TB on sale and then the upgrade cost to a CTO becomes way more than $400. Closer to $700.

Usecase: maillplane, safari, chrome, word, excel, bbedit, slack, Trello, music, photos, podcasts. Small photoshop edits of graphics, and a few times a week 1080p premiere projects, most under 10 mins and a few 30 mins. Simple videos with a few graphics and employee submitted smart phone videos. The last premiere export for a 30 mins video took 7-9gb of ram (but I'm not multitasking, just letting it run)
 
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MathChief

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May 21, 2020
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I have encountered two cases when 16 GB is far from enough.

(1) I need to solve some moderately large linear system (for Maxwell equations' discretization in the mid~high frequency regime so iterative solver is not available), I have to use MATLAB's mldivide to do a direct solve. When the degrees of freedom exceeds 3 million, the RAM goes boom to 16 GB and out of memory quick.

(2) Training of a customized structure graph convolutional neural network for molecular quantum chemistry in TF 2.0. In this case, you cannot take advantage of the Dropout and other tricks, and you have to load all parameters at the same time in order to train. My experience is that a net with 2 million parameters and with a batch of 64 sample molecules, 16 GB is gone.

Cannot wait to update my gear to a 32GB one in 2021 (still rocking on a Macbook pro 2013 but decided to skip the disappointed MBP 2020).
 

||\||

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Nov 21, 2019
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I often touch 16gb with 20-30 chrome tabs open in 2 different windows. Along with ms words, safari, excel, vpn, and couple other gadgets. So I’ll probably get 32gb. Also ram ssd swapping will wear down the cells in ssd, given how the ssd is not even user replaceable anymore in Mac, I wouldn’t memory swap between ssd and ram on a regular basis
Since compression has been a thing, memory pressure is what you want to be watching. This is what tells you whether you need more RAM, not specific RAM usage. Working on large-format vector graphics in Illustrator, with podcasts going, and some browsers tabs and other work apps open, I am at 11.5GB out of 16GB. Memory pressure is still green and relatively low. This tells me I do not need more RAM. The system will begin compressing as necessary. It will be yellow when I am approaching the limit and RED when I am over. I seriously doubt your use of browser tabs and office applications would require 32GB RAM. As a large-format production artist, I don't need it.

Screen Shot 2020-05-21 at 06.19.56 PM.png
 
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pshufd

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Oct 24, 2013
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Question. Does the same app on a 16 vs a 32 machine consume the same amount of ram? i.e. if Chrome is open with 10 tabs and it consumes 4gb of ram on a 16, does it consume 4gb on a 32 with the same tabs or more because more is available?

I know the OS on a 32 uses more since it's available but do the individual apps? Considering the 16 vs 32 argument myself as the base upper tier 16/1TB on sale and then the upgrade cost to a CTO becomes way more than $400. Closer to $700.

Usecase: maillplane, safari, chrome, word, excel, bbedit, slack, Trello, music, photos, podcasts. Small photoshop edits of graphics, and a few times a week 1080p premiere projects, most under 10 mins and a few 30 mins. Simple videos with a few graphics and employee submitted smart phone videos. The last premiere export for a 30 mins video took 7-9gb of ram (but I'm not multitasking, just letting it run)
In Firefox, there's a knob where you can get better performance at the cost of more RAM.

In TD Ameritrade Think or Swim, you configure the max memory that the program can take.

So you can tweak some programs for better performance at the cost of additional RAM.

In general, if RAM is cheap, go for it. It's crazy cheap on PC desktops these days. I'd love to throw 96 GB of RAM in my old desktop but I don't know whether or not it can take 16 GB DIMMs.
 
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KPOM

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Oct 23, 2010
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I like to imagine it's 2027 and I'm about ready to retire my 2020 MacBook Pro. What amount of RAM will likely be considered standard by then? Might having 32GB of RAM give me a year or three more of non-sluggish performance than 16GB would have? Even if I don't need that much right now? Maybe!
My guess is that 16GB in 2027 will be like 8GB today. I.e. still enough for most users but the “Pro” models then will have 16GB standard with 32GB a common upgrade.
 
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ctjack

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Mar 8, 2020
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I like to imagine it's 2027 and I'm about ready to retire my 2020 MacBook Pro. What amount of RAM will likely be considered standard by then? Might having 32GB of RAM give me a year or three more of non-sluggish performance than 16GB would have?
Let's look at this the other way around.
1) If you bought MB Air i3 with 8gb ram then you spent $1000 now.
2) If you bought MBP 13 base 8gb ram then you spent $1300 now.
2a) Higher base of MBP is $1800.
3) If you bought MBP 16 base you spent $2000.
So by going this logic you can update with new Air every 2 year period, base MBP 13 every 3rd year, higher base 13 every 4th year, and MBP 16 every 5th year.
By going base Air route you will have 2 laptops in 4 years for the same price of $1800 MBP.
By updating regularly you also get the latest tech in your laptop and they could even give you 16gb of ram as a base option.
 
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KPOM

macrumors Pentium
Oct 23, 2010
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In Firefox, there's a knob where you can get better performance at the cost of more RAM.

In TD Ameritrade Think or Swim, you configure the max memory that the program can take.

So you can tweak some programs for better performance at the cost of additional RAM.

In general, if RAM is cheap, go for it. It's crazy cheap on PC desktops these days. I'd love to throw 96 GB of RAM in my old desktop but I don't know whether or not it can take 16 GB DIMMs.
macOS is far more efficient at using RAM. I’ve had my 16GB Ice Lake MacBook Pro for 2 weeks now, and despite running a Windows 10 VM, I have yet to see a single swap to the SSD. I don’t run anything RAM-intensive, but given that running a VM in itself takes up 4GB, I think that’s significant.
 
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mmomega

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For myself, Safari and 4 tabs, mail, Lightroom and Photoshop, iMessage and I'm pushing 29-30GB RAM.
2019 i9 2.4 8Core, 32GB, 1TB, Vega20
Screen Shot 2020-05-21 at 11.37.26 PM.png
 

KPOM

macrumors Pentium
Oct 23, 2010
15,033
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For myself, Safari and 4 tabs, mail, Lightroom and Photoshop, iMessage and I'm pushing 29-30GB RAM.
2019 i9 2.4 8Core, 32GB, 1TB, Vega20
View attachment 917508
But only 4.67GB is wired, and you have used 0 swap space. Remember the OS will use whatever RAM is available to it. My guess is that on a 16GB system, you’d be reporting that you are right around 14-15GB.
 

mmomega

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Correct. Swap is when the system will use the hard drive, SSD, etc outside of available RAM.
Wired is what macOS is setting aside to use.
App memory is what the applications are currently using.
I can easily get in to swap if we need to go that route. So if I did more day to day work on the MacBook I would more than likely choose 64GB but it won't ever be the main. So I couldn't see going with 64 whenever the next upgrade is but things may change by then.

I am not sure if a 16GB system would show different.
I just do know that on the 32GB Mac Mini, the memory usage is very similar, app memory and wired.
The 64GB iMac Pro shows very similar total usage, with the same apps open. I also run 2 VM's on that machine at the same time so I will get into 40GB RAM easily day to day, with wired RAM being in the 4-5GB area.
And almost exactly the same on the 64GB iMac.
None of them climb on RAM usage just for having for RAM in the system, they are for the most part mirror each other when under the same workload.
 

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