# Buying a new iMac - How much RAM?



## salsindoddy (Feb 1, 2021)

Very soon I will be buying a new iMac to replace one that is now 10 years old and has reached  the point where it will not run the latest version of several programs I use.
I understand that Lightroom is very memory hungry and that lack of RAM can slow it down considerably.  Ten years ago I specified 16GB which seemed "overkill" at the time but now seems to be the "minimum" to run successfully. I read reports recommending 32GB "or more".
I'm now in my late 70s and am hoping that this new machine will be the last one I need to buy, so I'm prepared to up spec. it to see it well into the future.
The new machine will be a 27", with 3.8GHz Intel i7, Radeon Pro5500XT and 1TB of SSD storage.
I have one collection containing about 50,000 photos.
My question  is simple. Do I go for 32GB of memory or, as some reports seem to indicate, will Lightroom be even happier with 64GB? 
(Cost is not an issue - I just want the best spec. for now and into the future.)
Thanks,
Mike Dodman
(Technology changes constantly and this topic may have been raised in the past, but I would like to hear what the experts think "now", not maybe 2 years or more ago.)


----------



## BarrySchwartz (Feb 1, 2021)

I think you're on the right track: more memory is always the way to go, and will help future-proof your computer.  My 2011 iMac, which I keep around for backup purposes, has 32 GB memory and a 1 TB SSD I installed, and it has made it possible to still use it on the rare occasions I need it.  These days, since you may be able to specify the graphics card, the most powerful card you can get will also be extremely useful; in some cases more than the memory.  The SSD is a non-issue, since I don't believe they even offer anything else.  Photos only get bigger and video, too.  All these items make processing go faster; even when time is not money, it matters.

You'll love the new screen, as well, a fabulous improvement over what came before.


----------



## clee01l (Feb 1, 2021)

I think Lightroom will consume somewhere between 16 and 32 GB of RAM I don’t think it will consume much if any above that. If you are running lots of other RAM intensive apps along side Lightroom you might consider more than 32GB. Where any app gets slowed down is when there is a need for more RAM than is available, Then unused parts of the app in memory are swapped out to the SwapFile to be swapped back in when requested.


Sent from my iPad using Tapatalk


----------



## DCBolton (Feb 1, 2021)

RAM usage depends on how many processes and which processes you run simultaneously. Modern OS's are multitasking and multithreading so it is possible to have much higher demands on RAM than any single program or process requires. I often have LrC running multiple processes along with other programs. My Win 10 system has 64 GB RAM, 512 SSD "C" drive and 1 TB SSD scratch drive for PS, LrC and Helicon Focus. I never regret having all 64 GB and would have more if it were possible. Get the max if money is not an issue. 

Sent from my SM-N960U using Tapatalk


----------



## Conrad Chavez (Feb 1, 2021)

The most important thing is to order no less than 32GB RAM. Lightroom Classic does prefer over 12GB RAM so that it has enough RAM for caching as many previews as it can in RAM for quick display. When editing a single image, I don’t see it go much above 16GB, but that still means you want more than 16GB for the system and other running applications to get what they need. The only time I see Lightroom Classic go significantly above 16GB for itself is when merging multiple images into a panorama or HDR. That is how I arrived at 32GB as a safe ceiling. For Lightroom Classic alone, 64GB won’t do much.

The more other applications you have open, the more 64GB will help. You should get 64GB if you frequently run both Lightroom Classic and Photoshop at the same time, especially with high megapixel files. Other reasons to get 64GB is keeping several pro applications open simultaneously for photo and video editing, or running another operating system (such as Windows) inside a virtual machine while running Lightroom Classic.

In brief, you can make a case for 64GB for this next iMac, even though Lightroom Classic itself probably won’t need more than 20-24GB. The rest would be for other applications.

Another option: RAM can be upgraded later in the 27-inch iMac, so get 32GB now, see how that goes, and you can add more later yourself. A RAM upgrade will be cheaper from a non-Apple source anyway.



DCBolton said:


> Get the max if money is not an issue.


Good advice in the past, but there isn’t much to gain from maxing out RAM for Lightroom Classic on a current Mac or PC. The maximum RAM you can put in an iMac is 128GB, or 256GB in an iMac Pro — yet it is unlikely that Lightroom Classic itself would take advantage of 128GB or more in the next few years. The reason to max out RAM is for handling extremely large and high megapixel files in Photoshop,  handling very large data sets in other applications, running multiple VMs, things like that. But Lightroom Classic itself won’t benefit from maxing out the RAM.


----------



## kimballistic (Feb 2, 2021)

Please do yourself a favor and order RAM from a trusted third party like OWC's macsales.com:

Memory Upgrades for 2019-2020 iMac 27-Inch - Up to 128GB

The iMac is one of the last Apple machines with user-upgradeable RAM.  128GB from Apple costs around $2,000.   128GB from OWC costs $600.  FYI.


----------



## Rob26 (Feb 2, 2021)

Hi Mike
Almost in same situation as yourself. I have 2010  iMac 21"  The issue for me is the promised new 24" iMac with the new M1 ? processor
just round the corner. With apple changing over to Silicone chips how long will Lightroom be supported on the old system?
Be aware that Apple Silicone is a big move away from the present Intel processors so I have no idea what that really means.
I have been looking at the Mac Mini models and a separate Wide Gamut monitors. But even that is not straight forward,with loads of issues cropping up.


----------



## BarrySchwartz (Feb 2, 2021)

Rob26 said:


> Hi Mike
> Almost in same situation as yourself. I have 2010  iMac 21"  The issue for me is the promised new 24" iMac with the new M1 ? processor
> just round the corner. With apple changing over to Silicone chips how long will Lightroom be supported on the old system?
> Be aware that Apple Silicone is a big move away from the present Intel processors so I have no idea what that really means.
> I have been looking at the Mac Mini models and a separate Wide Gamut monitors. But even that is not straight forward,with loads of issues cropping up.


The other issue relating to the older Macs is that they don't support the more recent OS or 32-bit software, with the result that many kinds and brands software won't work on the older Macs.


----------



## salsindoddy (Feb 10, 2021)

Many thanks to all for your thoughts on the subject.
Rest assured, all additional RAM will NOT be bought from Apple.


----------



## camner (Feb 12, 2021)

Last fall I purchased a new 27" iMac, replacing a 2015 edition of the same.  On my old machine, I had 32GB, but my swap file was used regularly, and often was fairly large, indicating that the iMac need to write out the contents of RAM to disk fairly regularly, which slowed down the beast.  I decided to get 64GB (from OWC) in my new iMac.  I have rarely seen my swap file get at all large, and is often at 0.  I do have to admit that I keep lots of things open at the same time (including many Chrome tabs/windows, which chews up a lot of RAM).

A potentially important note:  My new iMac was one of the earlier ones off the assembly line (I bought it about a month after they first came out), and there were many reports of problems with non-matching RAM sticks. For example, I purchased 8GB with the machine, and then added two 32GB sticks from OWC, but the iMac wouldn't boot.  Apple eventually put out something that said that the only configuration that was officially supported was to have all of the RAM sticks be of the same size and manufacturer.  I took out the two 4GB Apple sticks, and my iMac has been happy ever since.  I don't know if Apple made changes to the iMac in the meanwhile to render this no longer necessary, but you should know that it WAS an issue, and still might be.


----------



## Rob26 (Feb 12, 2021)

Right now I think the important thing to do is research on the new line of M1 chips being installed in Mac. Apple are moving away from Intel
processors and going for an integrated system. The memory is part of the chip. so you cannot upgrade memory. However that what you purchase is supposed to be far more efficient. That is why I suggest you hold back a bit. If you buy an iMac now plus your memory, might you be
getting into a system that is being phased out?
I am holding back until the new iMac is released then I can make a more future proof decision.
Rob


----------



## michaelp (Feb 17, 2021)

Possibly too late now, but whatever you do don't buy RAM upgrade at purchase time! Apple's charges for extra RAM are insane. The RAM in a 27" iMac can still be manually upgraded by popping open a little panel on the back (the release button is in the power socket recess).

FWIW I have a Mac mini 2018 (6 core) and with the initial 8GB RAM I still had hiccups running Lr (6.14).  I upgraded to 32GB myself (fiddly!) and it's now incredibly smooth.

But that may have been overkill. Perhaps you could look at Activity Monitor while running Lr to see how much memory is in the SWAP file (ideally zero!), or use a tool like this XRG (free) which amongst many other useful things shows real time RAM usage.


----------



## michaelp (Feb 17, 2021)

Rob26 said:


> Right now I think the important thing to do is research on the new line of M1 chips being installed in Mac. Apple are moving away from Intel
> processors and going for an integrated system. The memory is part of the chip. so you cannot upgrade memory. However that what you purchase is supposed to be far more efficient. That is why I suggest you hold back a bit. If you buy an iMac now plus your memory, might you be
> getting into a system that is being phased out?
> I am holding back until the new iMac is released then I can make a more future proof decision.
> Rob


One thing to bear in mind is that - I understand - you will not be able to run windows on the new M1 (ARM) Macs.


----------



## michaelp (Feb 17, 2021)

Conrad Chavez said:


> Good advice in the past, but there isn’t much to gain from maxing out RAM for Lightroom Classic on a current Mac or PC. The maximum RAM you can put in an iMac is 128GB, or 256GB in an iMac Pro — yet it is unlikely that Lightroom Classic itself would take advantage of 128GB or more in the next few years. The reason to max out RAM is for handling extremely large and high megapixel files in Photoshop,  handling very large data sets in other applications, running multiple VMs, things like that. But Lightroom Classic itself won’t benefit from maxing out the RAM.


FWIW I have 32GB in my 2018 Mac mini (6-core) and the swap file sits at zero. But then I don't run Chrome or have a zillion apps open when I'm working in Lr.


----------



## jdposthumus (Feb 23, 2021)

DCBolton said:


> RAM usage depends on how many processes and which processes you run simultaneously. Modern OS's are multitasking and multithreading so it is possible to have much higher demands on RAM than any single program or process requires. I often have LrC running multiple processes along with other programs. My Win 10 system has 64 GB RAM, 512 SSD "C" drive and 1 TB SSD scratch drive for PS, LrC and Helicon Focus. I never regret having all 64 GB and would have more if it were possible. Get the max if money is not an issue.
> 
> Sent from my SM-N960U using Tapatalk


Fully agree. I used to work in Lightroom Classic on my iMac 2013 running on 32GB RAM and frequently needed to free up memory using CleanMyMacX. Sometimes this would not even help I would have to reboot. Now I run Lightroom on a MacBook Pro 2019 (2.4 GHz 8-Core Intel Core i9) on 64GB RAM. I do not regret paying for the extra RAM for one second.  Although I still need to free RAM periodically, I can work much longer before that becomes necessary.  If you can afford it, then get the 64GB!


----------



## tsinsf (Feb 23, 2021)

The new silicone M1 chips have changed the rules for RAM. It seems like the new models will require less RAM than the old Intel models to get the same effect. How much RAM in an M1 model equals an amount of RAM in an Intel model is not clear yet. But it sure seems that less is needed.


----------

