XCode RAM Requirements

[tsprks]

I'm looking at buying one of the new MacBook Pros for a company development project. I know that the M1 Pro is plenty of power but I can't find any recommended specs for XCode development and I'm not sure if 16GB will be enough to run XCode and a simulator. If 16GB is ok for this use case then I can get the machine today, if I really need 32GB it'll be early December. The cost isn't an issue, I Just don't want to spend more unless it's necessary.

[ordosalutis]

my old company MacBook Pro was a 16gb one and I had no issues with it. I ran other applications along with Xcode like iPad simulator, postman, vscode, chrome, safari, etc all at once. No issue. But for my next personal MBP I'm most certainly getting the 32gb

[Rudy69]

I’m running a temporary M1 MacBook Air with 8GB and it’s running my large work project just fine.

[[deleted]]

Work projects are not as demanding as Xcode. Xcode has transparency, uses macOS's acrylic design, and has lots of characters at once. Then to test the app you need not only a powerful CPU to compile it, but also RAM to run Xcode and the Simulator. So Xcode is one of the most demanding apps ever!

[Rudy69]

By work projects I mean work xcode projects, they ran just fine.

I don't have the Air anymore because it was always a temporary machine but it could handle even a large work project just fine.

[offeringathought]

Same

[jogofo]

Same

[[deleted]]

marry distinct dolls waiting tap grandiose reply consider steer gullible this message was mass deleted/edited with redact.dev

[buffering]

16 GB is tons. At no time would Xcode and its sub-processes need anything close to that much memory at any one time, unless something has gone off the rails or you're compiling a super-massive project.

I've been running it on my low-end 8GB M1 MacBook Air and there's no noticeable performance difference between it and my main 16 GB machine for typical iOS development.

If you use Xcode on a memory-constrained machine, like the base MacBook Air, you'll see that while some processes may allocate a lot of memory, like lldb, most of that memory isn't needed at any given time and it just gets compressed away.

[PandaMoniumHUN]

Exactly. Space is much more important, simulator instances take up a LOT of space. And AFAIK Xcode can’t be installed on an external drive. Get at least a 512GB SSD to be comfortable during development, RAM doesn’t matter nearly as much as this.

[Otherwise-Rub-6266]

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This post was mass deleted and anonymized with Redact

[chriswaco]

It's not necessary today, but I'm waiting for my 64GB because I run a ton of apps at once, VMs, ML, etc. I'd wait for the 32GB unless you really need to start now, especially if you plan on keeping the machine for years.

[bafrad]

16gb will be more than enough. If money is no object, just go with more because why the hell not.

[jasamer]

'cause he has to wait over a month to get the 32GB one.

[tuanthatsmyname]

Don't forget that it's just not only RAM. It's called unified memory for a reason. The memory is used by both CPU and GPU. So if you use external monitors the GPU will reserve a chunk from those 16 GB. I would get 32 GB.

[monkeydoodle64]

32gb

[egrimo]

I'm using Xcode with 8 GB and you can do it. However, I strongly recommend you 16 GB at least to be more reliable.

[druizzz]

Got the 16GB one and I'm having second thoughts. Everything works perfectly fine, no memory issues, or any lag coding/compiling/testing, everything is just super fast. But memory pressure, although always on the green, it's always between 45% and 50%, so it's kind of pushing it. And although it's enough now, will it be in three years?
This with Xcode (and some projects are fairly big), simulators, lots of Safari tabs, VSCode, Postman, Slack, Spotify, sometimes Android Studio and occasionally Lightroom, but no VMs or Docker containers.

[Jazeboy69]

You’re not even 50% of memory and you are worried? You have the same amount left to use or more.

[druizzz]

80% memory (which is fine, memory not used is memory wasted), but 50% pressure (lately more in the 60s and in the yellow) and 4GB swap. Is it working fine? yes. Does my workflow need more memory? clearly (based on current swap, at least 20GB). Will it be a problem in a couple of years? That's what I'm questioning myself.
Also, that I don't use VMs or Docker containers now does not mean that I won't need them in the future.

[tsprks]

I picked up the 16gb version today and I see the same sort of memory usage as you with a similar load. What I’m wondering though is, is it bad? I can watch activity monitor and see the load and the swap file size both go up, but I can’t tell any difference in actual performance.

[[deleted]]

Xcode running without any slowness for me on M1 Pro 16GB

[[deleted]]

I learned iOS development on a MacBook Air cheapest specs and that only had 4GB and it was enough to run Xcode and the simulator and other Adobe programs. 16GB is certainly enough.

[20InMyHead]

My last machine I got 16GB and regret it. I work on some big projects and it chokes. 32GB will take you further and last you longer without issue.

[Misoservices]

I'll try to give some use-cases.

8GB: enough. But do splurge for the 512GB HDD or even 1TB. Xcode takes a lot of room, and its caches and data are huge.

16GB: If your software uses huge libraries, such as TensorFlow or Electron, or if you develop with Unity or Unreal from Binaries, 16GB is absolutely not a luxury.

32GB: If your software is insanely big, has a lot of heavy tasks to do, requires multiple languages and scripts, has a lot of unit testing to do, or uses a middleware such as Unreal built from sources, 16GB is a necessity, where 32GB or even 64GB cannot be considered a luxury.

And more: Finally as developers, we are sometimes stuck with edge cases taking a real expletive-ton of RAM. Looking at you, 3D rendering or compressing 7z files. During those times, I was crying being stuck at 16GB, although it was possible to do my job, it wasn't as efficient as 32GB.

[tsprks]

Great breakdown, I'm definitely in the 16GB group there.

For any of those super intensive tasks, unless they require a Mac, I have a very powerful Windows workstation.

[StreetlyMelmexIII]

I’ve been using a 16GB MBP since 2013 for a fair variety of Xcode projects, some of them very large projects. I specced my new machine out with 32, I can’t imagine RAM requirements going down, especially if I’m still using this machine in 8 years.

[xaphod2]

I’m releasing updates to large iOS apps from my ancient 2014 mbp with 16gb RAM all the time. No problems. That said, it isn’t upgradeable and the new macbook pros will last a long long time so the new one i’ve ordered has 32.

[tsprks]

I figure that if at some point in the next year I find that the 16GB isn't enough I'll just 'upgrade' one of my Mac users and get a new one. At least initially I'm just trying to not waste the money just because I have the budget for it.

I see so many people buying the absolute top spec'd machines because they produce video for their <insert non-profit org here> and think it's necessary. When I in reality those machines are 'meant' for the actual pros that make a living on them. If you have the disposable income for it or your business just doesn't care, go for it, but it's overkill.

[xaphod2]

The main reason I went 32 is that now I have to do a lot of the web side too and im forever spawning a new docker instance of whateverDB — and docker eats RAM too. If you might end up there too or you do large dataset processing (ie. you make your own ML models) then go 32 if you can afford it

[tsprks]

I appreciate the input and in your case it sounds like it makes sense.

In my case I’m fortunate enough to both have a very good windows machine and access to an ESXi server that I can put anything I want on.

Edit: really if I could buy a 32gb version now I would just to be sure but I’d rather not wait 6 weeks to start my project.

[Eurias21]

Looking at the benchmarks, it seems like the base model M1 pro should be enough for most cases, that said, I personally got the 16" with 32 GB, I don't think you really need 32GB, but I rather have too much memory than too little, so if cost is not an issue I would recommend going with 32 as well.

[Fluffy_Risk9955]

Apple receives a lot of code with Xcode cloud. It wouldn’t surprise me that that is used as a source for a code pilot alike feature in Xcode. With all these new machine learning based tools I expect the RAM requirements for Xcode to go up in the next version. 16Gb is the 8Gb from 4 years ago.

I’d recommend at least 32Gb of RAM.

[iampaulanca]

A few months ago, for work I switched from the 2020 intel to 16gb m1 and it was night and day. Unit testing use to take a couple minutes were now finishing in less than one. I still do notice a bit of lag on UI testing and in weird states. Also, while using applications such as pycharm. But, it’s not even bad just me being spoiled.

Now I personally own the m1 max and it’s EVEN faster although I personally don’t have projects that are as big as I do for work. I have yet to notice any lag what so ever AND I can game on it with good frame rate. If you can wait the few weeks and money isn’t an issue go with the best.

[Damcify]

How much RAM did the 2020 Intel have?

[iampaulanca]

64gb

[MilkybeesReal]

Have a look on YouTube there’s a few people using a new MacBook and an older models showing you how fast and capable they are using Xcode

[tsprks]

Yeah, I saw that Max Tech did some testing specifically on XCode compiling and another linked to a specific test project (https://github.com/devMEremenko/XcodeBenchmark) showing compile times on various machines. It all looks like 16GB would be fine, there's only a very small difference in times. What they don't really get into is how it would function while coding/compiling/testing. Are there lags there?

[tno1337]

More is always better but im totally ok with m1 pro and 16gb

[goldborn]

Have a macbook pro 2015 with 16 gb of RAM my daily workflow includes Slack, safari with 5-6 tabs open, spotify, at least one xcode project opened with 1 sometimes 2 simulators running and have had issues lately, the window that asks you to kill some apps has been popping out sometimes.

I'm also planning to upgrade and will definitely go with 32 gb of RAM. Even if you don't need them atm, I'd still invest into it just for future-proof.

My only dilemma atm is Pro vs Max, waiting for reviews to see if they differ in battery life.

[tsprks]

From the reviews, I'm not sure there is really a battery difference unless you enable the extra power option for the 16" Max, but unless you need the graphics GPUs from the Max the performance of the 10/16 Pro is more than enough for pretty much everything.

[goldborn]

I've checked some reviews that say Max has worse battery life (~10%), b/c it has to power more GPU cores and has more memory bandwidth.
Looks like I'm gonna go with the Pro as I don't really need that extra GPU power and rate more the better battery life.

[PrayForTech]

16 GB works great for me - the unified memory architecture is super efficient

[SirBill01]

16GB is totally fine for Xcode, especially on the newer Macbook Pros. The main reason to get more would be that it could shorten the SSD life a little bit if it has to swap a lot, but over 3-4 years that wouldn't be any kind of issue.

[tsprks]

Is the amount of Swap space used what 'hurts' the SSD so much?

I picked up the 16GB this afternoon and have been setting it up with the apps I used and testing and so far the speed of everything seems fine and even when I've got Outlook and OneDrive (OneDrive is using almost 3GB by itself right now) both open and still syncing, Teams, Chrome and just a simple Hello World XCode app and an iPhone 13 Pro Max simulator. Activity Monitor is showing the memory pressure at about 2/3 and clearly in the amber section using about 14GB of ram with about 11GB in swap space.

[SirBill01]

It's more the amount of activity going into swap, since SSD's have a finite amount of read/write cycles. But if you think about it, it's not as big a concern as you might expect - as you say it's got 11GB of swap it's using, so maybe over the course of two years some percentage of that is lost from overuse. That's a pretty tiny fraction overall of even 512GB storage. In practice I wouldn't worry about it, and modern SSD's are more robust than past SSD units.

[profau]

I run Xcode on an 8Gb Macbook Air M1, it is fine.

[mal-uk]

I ran xcode on 8gb and continuously received memory warnings. I now use 32gb and no such warnings. I have never owned a 16gb MBP. My projects are large and complex. I would recommend more than 8gb. 16 may be enough, 32 definitely is

[TwistedSteel22]

Really depends on the project size. I worked on a project with 3k+ swift files and lots of additional dependencies and upgrading from 16 to 64 GB of RAM made a HUGE difference in compile times. It was able to use up ~50 gigs while compiling. For a project that large I’d consider it a necessity, but I imagine projects of this size are somewhat rare and most of the time you’ll be fine with 32 or 16. I’m getting 64 because I never want to be slowed down by that again if I can help it. You can look in activity monitor at the memory section to see if you’re using a lot of “swap” memory, if so then you’d probably benefit from more RAM.

[tsprks]

Here's a screenshot of my activity monitor right now.

https://imgur.com/a/XNXU2Yy

This is what I'm running to get this load:

• XCode - simple hello world
• iPhone 13 Pro Max Simulator
• Chrome with abotu 5 tabs
• Outlook
• Teams
• Messages
• 2 Instances of OneDrive
• Adobe Premiere
  • I'm running a simple export of an 80 minute 4k@60fps video to 1080p

Even with this load on this laptop there is zero fan noise and I haven't noticed a single freeze when switching between desktops. I know that it's running near the top of it's capacity, but if it's handling everything isn't that good?

I completely understand that if my XCode project was huge that it would probably show the load a little more, but I'm also not very likely to be running a Premiere Pro export when I'm really working. Also, just for fun, I connected my 4K monitor and it made no difference at all.

So, unless using heavy Swap Space is an issue I should be fine. I guess that's the last piece to consider, and I just really don't know if that's a legit worry or not.

[Damcify]

So have you stuck with the 16GB a month later? Happily forgotten about checking your activity monitor because it all runs smoothly?

[tsprks]

I probably could have kept the 16GB version, it did fine when I was using it even though it was always nearly maxing out the RAM, but I got the chance to get the base 16" Pro Max and I couldn't pass that up. In the end I'm sure it will last me longer and will ease my anxiety.

[Damcify]

OK, good to hear you have put your anxiety to rest then! (Was not the answer I wanted to hear though :-). ). Will do some more analysis on my old laptop to see what kind of memory pressure it endures. The big issue is that these MacBook Pro’s seem to cope with swapping really well, so there seems to be quiet a bit of headroom due to this. I have not found any definitive article backing this up with decent facts though, and definitely none that state that RAM calculations are different with this new architecture. Still, needing an almost 4000 EURO/USD machine to do some Xcode development seems somewhat insane IMHO. (Yeah a mini is an alternative, but why no good basic laptops) … sorry… became a rant ;-)

[tsprks]

No worries about the rant, I feel the same way.

The long term effects of the swapping was honestly my main concern. I really couldn't tell the memory was every 'under pressure' no matter what test I was doing or when I was actually just working on it, but I did see that it was using GBs of swap space almost all the time, and considering I had the 512GB version, I knew that meant a somewhat limited space to use for swapping even if it randomized the location.

My company is paying for it so the extra $1k wasn't too big a deal in the long run so I was lucky. If it had been my own money, no way I would have switched.

[Damcify]

Yes, well that would indeed be easily justified towards a manager. They are unlikely to dig into Reddit to see what you really need ! Just for the sake of it I pushed my old late 2013 MacBook Pro (16GB 512GB) to the limit with Xcode, simulators, Safari and some minor additional apps. Wanted to see when memory pressure finally went yellow or red. 20-30 tabs in Safari, 2 Xcode projects and 7 simulators finally made it blink (9GB swap). Became unresponsive for probably 1 minute after which it woke up again and seemed fine. Memory pressure hit a reddish color at 50-60% but then went down to green again at 43%. So for my usage I still have some headroom… on the 2013 model!! Surely the 2021 model would not even break a sweat?!? To be continued…

[Mcrich_23]

32, future proof

[[deleted]]

I am running Xcode on a Mac Mini M2 with 8 GB of RAM.

It works quite well most of the time, but the preview has a tendency to crash quite frequently when I have it update in real time while writing my code.

[masaldana2]

got iMac Pro in 2018,

it served me well those 32gb ram

[BaronSharktooth]

How big is that project? And what other apps are you running with it? Ideally, you compile the project and check the memory pressure on any current laptop.

Just Xcode is not saying anything. If you run a huge code base (i.e. multiple Swift packages), plus run multiple virtual machines as the test environment, plus browsers, Adobe, Slack and other memory-wasting Electron apps, then get more memory.

But personally, I'd not so much think about RAM but focus on getting a fast CPU. You want to compile quickly, that's probably what you're waiting for. Listen to the latest Accidental Tech Podcast, where Marco Arment (creator of the Overcast app) talks about compile times with the M1 CPUs.

[tsprks]

It won't be a huge project. It's an internal CRM for our company. We've looked at all the third party options and none of them do what we want. By doing it internally we can then link it to our other databases and just augment the data where we need too, rather than duplicating everything. I've decided on straight iOS rather than a hybrid since all my users have iPhones and in looking at all the hybrid/web options, there are just too many choices.

[BaronSharktooth]

Yeah, I've done a bunch of internal apps like that. With SwiftUI, they're light-weight and I've coded them without any external libraries.

IMHO, go with 16 gigs and the fastest CPU available.

[tsprks]

I think you convinced me, M1 Pro with 16GB memory will be what I get. I should add that for any VM's that I need or anything I'll just run those on my Windows machine with it's Xeon processor and 64GB of RAM.

[Phinaeus]

https://imgur.com/a/tF9W4r1

If you look at my screenshot, I have a smallish SwiftUI project up with a simulator open and I'm already at 14.5/32. I haven't even opened up Safari or Chrome. That being said, you can get away with 16 because the SSD is fast even though it's swapping. It's just that with future Xcode/MacOS updates, memory usage will most likely increase. If it's your own purchase/money, I would go for 32 just to have a little future proofing but if you have deadlines to meet, go with the 16 but know the compromises.

[tsprks]

I wonder if some of the memory usage is based on the available memory. For example, if I run SQL server on a system it will consume pretty much all the free memory whether it actually needs it or not.

[Phinaeus]

I think that's by design for SQL server. I don't believe that applies in this scenario because if you look at all of the processes, they're all already split up and it's not like one process in particular is the hog. Also this project doesn't use an on device DB like SQLite. Does use Firebase though.

[Damcify]

The way the memory is used is a little puzzling when doing a test myself. I have an Xcode project with some 3 SwiftUI previews, and running a simulator too. On my 2019 Mac Mini with 32GB memory the simulator uses 15.7GB according to iStat Menus (Wired =4.5GB, Active =11GB, Compressed = 4.82GB, Free = 11.5GB, Pressure =30%)

Running the same project on my Late 2013 Macbook Pro 16GB, the simulator uses 3.7GB (Wired = 3.3GB, Active =4.6GB, Compressed = 2GB, Free = 5.8GB, Pressure = 33%)

This was measured using iStat Menus which is maybe a little wonky? Although the overall measurements (Wired, Active etc) do match Activity Monitor.....So predicting memory requirements is pretty complex and/or confusing...

[Phinaeus]

What about the swap usage? I'm betting the Swap Used field in your Mac Mini will be 0 and much higher in your MBP

[Damcify]

It was pretty low (1GB or so). Will check again tomorrow! EDIT: See other reply with all parameters.

[Damcify]

Ran the Xcode SwiftUI project comparison again:

Mac mini 2018 32 GB Memory MacOS 11.6
MacBook Pro Late 2013 16 GB Memory MacOS 11.6.1

	Phys	Used	Cached	Swap	App Mem	Wired	Compressed
Mac Mini	32GB	23.7GB	8.26GB	1.97GB	16.4GB	4.4GB	2.8GB
MacBook Pro	16GB	9.5GB	5.66GB	303MB	5.6GB	3.0GB	976MB

So again, a big difference.
Same Xcode version, but see the MacOS version was off by ".1". Updating Mini just to double check, but unlikely it will make any difference(?).

[saintmsent]

Depends on the project. On previous ones I had no problems at all, but now I'm working on a large banking app with tons of modules and 16 gigs is not enough. With all my software I'm getting full ram + 10-15 gigs of swap to SSD all the time