Disk space needed for OS

[Zettie1996]

I am going to buy my first iMac. I'm in doubt to go for the 512GB SSD or the 1TB SSD. How much space is needed for the OS? Is a scratch disk part of this (I am comming from windows ).
I will be using it primaraly for photo editing (Capture One/ Adobe suite). Perhaps in the future I wil be playing with Final Cut pro/ Logic Pro x.
So far I,ve selected the 3,7 GHz 6 core I5, Vega 48, 512GB or 1TB SSD and extra ram will be installed later.

 

[chabig]

The System directory on my 2018 MacBook Pro running Mojave takes 7.5GB.

 

[Zettie1996]

OK, so 512 GB should be (barely ) enough.

 

[chabig]

Yes. Remember that the System will also consume some space during the course of its operation for things like virtual memory. There are threads on MacRumors with members claiming System storage of 50-90GB. Personally, I never look at details like that because the OS manages it automatically. If there is space available, the system might use it. If space is tight, it will use less. Some of it might be due to local Time Machine backups or other needs.

 

[SalisburySam]

I have a 512GB SSD in my 2017 iMac and it has proven, for me, to be quite sufficient. I also have an 8TB hard drive connected for my backups and file storage so little is actually kept on the iMac.

Note that you can upgrade your memory very easily in the iMac, and you can also upgrade the SSD. However it is much harder to do the latter since you have to peel off the front screen to expose the guts to do so.

If you have thoughts of using some of the heavier duty programs like Adobe, Final Cut Pro, Logic Pro, etc., and have large files you’ll want to keep in RAM for manipulation, I’d suggest going for max RAM (32GB IIRC), and the 1TB SSD. The RAM can be upgraded by you at less cost that from Apple, but the $600 upgrade for the 1TB SSD might be worth getting from Apple at time of purchase. Better yet, find a refurb’d unit with these upgrades already in place.

 

[Fishrrman]

The software (OS & apps) that comes pre-installed from Apple amounts to about 22/23gb.

512gb SSD will be fine. Don't buy the 1tb SSD unless you have $$$ to toss away and not worry about.

 

[Zettie1996]

I have a 512GB SSD in my 2017 iMac and it has proven, for me, to be quite sufficient. I also have an 8TB hard drive connected for my backups and file storage so little is actually kept on the iMac.

Note that you can upgrade your memory very easily in the iMac, and you can also upgrade the SSD. However it is much harder to do the latter since you have to peel off the front screen to expose the guts to do so.

If you have thoughts of using some of the heavier duty programs like Adobe, Final Cut Pro, Logic Pro, etc., and have large files you’ll want to keep in RAM for manipulation, I’d suggest going for max RAM (32GB IIRC), and the 1TB SSD. The RAM can be upgraded by you at less cost that from Apple, but the $600 upgrade for the 1TB SSD might be worth getting from Apple at time of purchase. Better yet, find a refurb’d unit with these upgrades already in place.

[doublepost=1558386955][/doublepost]Thanks! I want to upgrade with 32GB, so the total amount of RAM will be 40GB. For the first years I will be using Apple care, so I don't want to replace the SSD in the near future yet. Refurbs are very hard to find here in the Netherlands, so it wil be a BTO.

The software (OS & apps) that comes pre-installed from Apple amounts to about 22/23gb.

512gb SSD will be fine. Don't buy the 1tb SSD unless you have $$$ to toss away and not worry about.

I find the extra €450 too much to spend for the 1TB, so I will be using an external T5 for my work and in my workflow I will be transfering this to the NAS (which is much slower).

 

[SalisburySam]

[doublepost=1558386955][/doublepost]Thanks! I want to upgrade with 32GB, so the total amount of RAM will be 40GB. For the first years I will be using Apple care, so I don't want to replace the SSD in the near future yet. Refurbs are very hard to find here in the Netherlands, so it wil be a BTO.

I find the extra €450 too much to spend for the 1TB, so I will be using an external T5 for my work and in my workflow I will be transfering this to the NAS (which is much slower).

Sound like a good plan. If anything you create is published anywhere, post some links for us to enjoy your work too! Good luck with your decision and purchase.

 

[codernova]

512GB has been perfectly adequate for System-Level development for me on my work MBP. I have 3 external SSDs I use to boot VMs from for Windows/Linux but my code/tools all reside comfortably on the internal SSD.

 

[mikehalloran]

You're not asking the right question. The OS, system libraries and your applications reside in the boot drive.

I will be using it primaraly for photo editing (Capture One/ Adobe suite). Perhaps in the future I wil be playing with Final Cut pro/ Logic Pro x.

The software (OS & apps) that comes pre-installed from Apple amounts to about 22/23gb.

512gb SSD will be fine. Don't buy the 1tb SSD unless you have $$$ to toss away and not worry about.

Don't listen to those who believe that, just because they don't need anything larger, you don't either. There's a reason that Apple makes up to 4TB available on the iMac Pro and those who need that much available can't do with less.

My system including Applications and support libraries is over 300GB. This does not count my work files which can be anywhere from 500GB up to 1TB or so—it depends on my active projects. If you are doing AV — and your post says you are (I do, too) — you need your work files on the boot drive for best performance. To work them from an external is slower even if the external is a TB 3 drive with the same speed rating.

Speaking of externals, the Thunderbolt 3, Samsung X5 is $1,000 for 2TB. How much larger SSD can you get for that? A USB external such as the T5 is 1/6 the speed of an X5.

A 512 would be useless to me. Just too small. 2TB is the right size for me.

You don't say if you do it professionally or not. If Time saved = Money earned, then more RAM, more cores and more onboard storage = better.

 

[HDFan]

My boot drive is 4 TB and I have used 2.4 TB.

~/Library is 1.1 TB. 646 GB is for mobileSync - backups of my IOS devices. 155 GB for techtool protection.

My Photos library is 337 GB.

On an external disk Adobe (cache, preview files,...) takes 774 GB. Ideally these files would be on my internal boot drive for speeds, but I decided to keep them external to save space.

My point would be that you need to look beyond Applications and System as there are other things that take space.

 

[mikehalloran]

My boot drive is 4 TB and I have used 2.4 TB.

~/Library is 1.1 TB. 646 GB is for mobileSync - backups of my IOS devices. 155 GB for techtool protection.

My Photos library is 337 GB.

On an external disk Adobe (cache, preview files,...) takes 774 GB. Ideally these files would be on my internal boot drive for speeds, but I decided to keep them external to save space.

My point would be that you need to look beyond Applications and System as there are other things that take space.

Interesting choice. Because having your Adobe files on the boot drive makes the app more efficient, those are not the files I would chose offload.

Since Mojave and iTunes 12.7, it is now easy to store both iTunes and Photos libraries onto an external without the hassle of using Symbolic Links. Why Apple didn't do this years ago is beyond me. Neither app is any slower this way with the libraries on a USB 3 external connected to my iMac Pro. Here are three articles that show you how:

These first two cover iTunes
https://appleinsider.com/articles/1...ving-your-itunes-library-to-an-external-drive

https://support.apple.com/guide/itunes/change-where-files-are-stored-itns2999/mac

Photos
https://support.apple.com/en-us/HT201517

Allowed me to offload about 800GB and go with a 2TB SSD instead of the $2,400 4TB upgrade

 

[HDFan]

Interesting choice. Because having your Adobe files on the boot drive makes the app more efficient, those are not the files I would chose offload.

Certainly would be faster (2395 MB/s on boot SSD vs 1048.5 MB/s read rates on external RAID), but putting 774 GB of Adobe files on my SSD would put my SSD close to the 80% threshold.

All photos and some of their libraries are on external drive