Why does macOS slow down with newer versions?

[Realityck]

I think it is a general thumb rule in the world of technology. Better technology needs better hardware.

Likely the underlying MacOS might be tweaked to be running more processes in the background as time goes by. Ventura is a lot more search based. Running graphics Metal 3 seems to run a touch busier when monitoring tempts when utilized actively. (FPS is slightly better)

 

[Ifti]

You can do that, however you are ignoring the security patches that come with more recent public MacOS updates. Ventura has made the spotlight search that more fast and useful. It not like this belief of slower and slower Intel Mac performance is that great a difference compared to you ignoring any security issues by doing what you are now doing. Ventura is not something that is noticeable slower, more like for you barely noticeable. Plus you need to just make sure you are backing yourself up to an external backup volume in case of some accident. We call that volume a ASR in which migration assistant file transfer completely restores you configuratio.

I'm still getting security updates for Monterey. Until that stops, there's no compelling reason for me to move to Ventura. In fact, its not just the hassle of checking and verifying software/driver compatibility with the systems I use, but also an added cost where software isn't compatible and I have to pay to upgrade that to the latest version too.

 

[izzy0242mr]

I'd like it to be a kind discussion. I'm expecting this, but saying just in case.

I have an unpopular and perhaps a little controversial opinion that Apple makes old devices obsolete on purpose. Most people I talk about with about this disagree. Most people think that adding features to software makes it slower. I'm a programmer myself and I know this is not the case. Unless this feature works in the background, it has no impact on performance whatsoever.

It's the same with iOS. When we install new versions, our hardware "naturally" becomes more and more obsolete. Or does it not? What is exactly happening in these new versions that use more resources all the time? I remember that before this "battery saving" (yeah, right) scandal blew up, every iOS version made home screen slower on older iPhones. I've been super suspicious about this, because making UI smooth is easy even in resource-hungry environment. It's just the matter of thread priority and Apple clearly didn't want to do this. And even that's assuming that something else used most resources of older iPhones, which I'm quite sure is not the case at all. Luckily, after the scandal they stopped it and now even a few years old iPhones are smooth on home screens.

I opened this topic as macOS thread, as I'm expecting more professionals here than in the iOS thread.

I feel like there are some thinking pattern traps that allow this to happen. One day I realized that it works like that with any software update. Once it's new and branded as "stability improvements", we feel like our software is super stable. Until there's next one - before we install that one, we feel like our previous one is no longer stable and we have bad quality software. But our software never changed! It's not like it got less stable over time. I hope you guys understand my point, because this shows the thinking patterns about hardware too. Many software requirements don't change, because this software remains the same, yet we are always pressured to replace our hardware, because if the new one is released, our becomes "obsolete". This is insane if you think about it. My favorite example are MacBooks, especially the jump from Intel to Apple Silicon. 16" Intel used to be considered a monster, until Apple Silicon came and 16" Intel became instantly "slow", even though the software we use was still the same.

Is anyone with me on that?

I have noticed this as well, more with older Macs but still.

I know other people says it's not true, but it makes sense logically as well as anecdotally:
1) New versions of macOS introduce new features while keeping old features. New features usually require more CPU and RAM usage. That means less CPU and RAM available for normal tasks.
2) New versions of macOS are occasionally designed with new more powerful hardware in mind. That means it's optimized to run on the best Macs. Older Macs may run it, but the target hardware for max performance is the newest hardware.

This was most notable for me in the upgrade from Snow Leopard to Lion. SL was really fast and snappy. Lion added cool features but was noticeably slower/had more frequent lag/slowdowns/hangups.

 

[untitledartists]

I have also thought a lot about the slow down of computers (iOS, Mac, Windows) in general over the years is a real thing or more an imaginary thing.
If you get used to a faster new computer, the old one which was rocket once seems like a Turtle then - so on the one hand slowdown is a perception thing.

On the other side slowdown is very real, especially the snappiness, boot time, responsiveness,....
A few of my examples:
My iPhone SE 2016 was perfect with iOS 10, everything was so smooth and fast as I remember. Now with 15 it is still great, but everything feels a little sluggish...and sadly I can not downgrade to see if this slowdown is only in my imagination...
But I have an other iPhone which I only updated once - an iPhone 4 with ios5 which I start just every few months out of curiosity. Unbelievable how fast and snappy the UI feels! And how much slower is the Processor/ GPU compared to an iPhone SE 2016 - 10x or 20x ? (and the SE itself is 5x-10x slower than iPhone 14, estimated from geek bench charts)
On Mac the same. My MBP 15 l2013 was turbo fast in 2014. I upgraded rarely, but tried until Mojave, Catalina, Big Sur. I hated the sluggishness which increased every update. So I went back and downgraded to El Capitan, which is snappy and still fun to use and still used by me for some professional video work.
Or an iMac 2009 27 C2D which I use in Target Display Mode - the Boot Time with an SSD on Snow Leopard is incredible - just a few seconds, and SL is so responsive and feels very snappy.

Long story short - I do not think the slowdown is on purpose (or maybe just a little ;-)
If you have more RAM, bigger and faster SSD speed, CPU/ GPU Speed, Internet Speed,....it is always used just for convenience..
All the Devs are developing on fairly new Machines, and when it is fast enough for them and fast enough for the majority of users it then the boss is happy.
Why optimise further and invest energy and money when it is "good enough"?

The update /upgrade cycles get faster and faster and more and more forced ("you have to because of security") - it is sad...

As other users in this thread I will upgrade as less as possible on all devices. macOS every three to five years. iOS one year after first release, or even skip one version if it has a bad reputation....
Never change a running system!

 

[FeliApple]

I have also thought a lot about the slow down of computers (iOS, Mac, Windows) in general over the years is a real thing or more an imaginary thing.
If you get used to a faster new computer, the old one which was rocket once seems like a Turtle then - so on the one hand slowdown is a perception thing.

On the other side slowdown is very real, especially the snappiness, boot time, responsiveness,....
A few of my examples:
My iPhone SE 2016 was perfect with iOS 10, everything was so smooth and fast as I remember. Now with 15 it is still great, but everything feels a little sluggish...and sadly I can not downgrade to see if this slowdown is only in my imagination...
But I have an other iPhone which I only updated once - an iPhone 4 with ios5 which I start just every few months out of curiosity. Unbelievable how fast and snappy the UI feels! And how much slower is the Processor/ GPU compared to an iPhone SE 2016 - 10x or 20x ? (and the SE itself is 5x-10x slower than iPhone 14, estimated from geek bench charts)
On Mac the same. My MBP 15 l2013 was turbo fast in 2014. I upgraded rarely, but tried until Mojave, Catalina, Big Sur. I hated the sluggishness which increased every update. So I went back and downgraded to El Capitan, which is snappy and still fun to use and still used by me for some professional video work.
Or an iMac 2009 27 C2D which I use in Target Display Mode - the Boot Time with an SSD on Snow Leopard is incredible - just a few seconds, and SL is so responsive and feels very snappy.

Long story short - I do not think the slowdown is on purpose (or maybe just a little ;-)
If you have more RAM, bigger and faster SSD speed, CPU/ GPU Speed, Internet Speed,....it is always used just for convenience..
All the Devs are developing on fairly new Machines, and when it is fast enough for them and fast enough for the majority of users it then the boss is happy.
Why optimise further and invest energy and money when it is "good enough"?

The update /upgrade cycles get faster and faster and more and more forced ("you have to because of security") - it is sad...

As other users in this thread I will upgrade as less as possible on all devices. macOS every three to five years. iOS one year after first release, or even skip one version if it has a bad reputation....
Never change a running system!

I can guarantee that you are not imagining the slowdown you perceive on your 1st-gen SE. I have an iPhone 6s on iOS 10 and one on iOS 13 and the one on iOS 13 is slow, has keyboard lag, and frequent hiccups.
The one on iOS 10 is flawless. If you could downgrade, it would be flawless for you, too.

iOS updates are malware.

 

[bearinthetown]

1) New versions of macOS introduce new features while keeping old features. New features usually require more CPU and RAM usage. That means less CPU and RAM available for normal tasks.

This an urban myth. There are features working in the background being added from time to time, but not often. Also, if these devices are as powerful as they're advertised to be, how come such a relatively lightweight piece of software as an operating system can make it sluggish? Operating systems are complex, but also lightweight in terms of what needs to be running all the time.

 

[thebart]

There's no need for Apple to slow down your system with new OSes. All they have to do is not care, and that is the cheapest most expedient and bottom line boosting thing in the world.

90% of OS development is driven by what features will make for a cool presentation at the next wwdc or whatever. What are we going to give the media to write about? And it's not going to be making this or that run a little faster, or fixing this or that long running bugs or annoyance, or simple long needed tweaks and additions. Because you can't have Tim Cook or some Pooh-Bah wax poetic about fixing Bluetooth issues or things window or android has had forever; they're going to be laughed at, even though these things actually improve quality of life for the end user way more than some new feature that is half baked and destined to become abandon ware.

 

[GMShadow]

It's best practice to nuke/pave on a machine after several upgrades. This includes iOS devices - it's why you see several people in here saying things ran better once they did an iTunes upgrade vs on device, etc. While macOS is nowhere near as bad as Windows XP was in terms of fragmentation, stuff still happens, and third party apps are often *very* bad about housekeeping.

 

[spiderman0616]

I've been using Macs my whole life and they've had their ups and downs, but one thing I can say is that since about 2011 when I got my Intel Mac mini all the way up until this very day, my Macs have never felt like they're "slowing down" from year to year. Maybe my Intel models got louder and hotter over the years as resources became more taxed, but performance remained what I expected for the time.

These days I'm on Apple Silicon. Of course, it's far faster than the old Intel Macs, but the old Intel Macs weren't slowing my workflows down. They were just making them more annoying because of all the baggage that comes with Intel processors in the way of thermal management.

But one thing has remained the same: I fly around macOS just as fast as I always have. Yes, it's a legacy desktop OS, but it's perfectly optimized for the hardware it's running on, and that's all I can really ask of it.

 

[MrScratchHook]

id like to chime in, im the furthest thing from a programmer(just need to put that out there) So im a mac user since 2007(the all white imac) leopard, snow leopard, lion, (imac 2011) yosemite, (2008 mac pro quad) yosemite, el capitan, (2012 mac pro 6 core) sierra(liked this macos, the most stable), mojave, (upgraded to dual 12 core and opencore) big sur, monterey. Out of all these versions the only difference i can recall is the opencore versions have slight hiccups where a setting reverts to default but those are the things i can live with being thats its a hacked system, but i dont see or feel any serious slow down issues that affect my usage. Now on the contrary, i bought a 2017 imac(2.7 duo core) that came with monterey last august because i wanted to install ventura when it came out in november, i then installed ventura and right away double clicking became an issue, every double click became a quadruple and sixtuplet click, was the worst experience i've ever had on any macos. Used ventura for 2 months, until i got tired and reverted to monterey and the double click issues disappeared and even my 10 year old daughter noticed the difference, now that says alot.....

 

[Fishrrman]

The hardware is "hauling a load".
The load is the OS.
As the OS progresses from one version to the next, it gets "heavier" (requires more to "haul it").
Thus, in some cases, the hardware will have a tougher time "hauling" the software...

 

[TBoneMac]

I'd like it to be a kind discussion. I'm expecting this, but saying just in case.

I have an unpopular and perhaps a little controversial opinion that Apple makes old devices obsolete on purpose. Most people I talk about with about this disagree. Most people think that adding features to software makes it slower. I'm a programmer myself and I know this is not the case. Unless this feature works in the background, it has no impact on performance whatsoever.

It's the same with iOS. When we install new versions, our hardware "naturally" becomes more and more obsolete. Or does it not? What is exactly happening in these new versions that use more resources all the time? I remember that before this "battery saving" (yeah, right) scandal blew up, every iOS version made home screen slower on older iPhones. I've been super suspicious about this, because making UI smooth is easy even in resource-hungry environment. It's just the matter of thread priority and Apple clearly didn't want to do this. And even that's assuming that something else used most resources of older iPhones, which I'm quite sure is not the case at all. Luckily, after the scandal they stopped it and now even a few years old iPhones are smooth on home screens.

I opened this topic as macOS thread, as I'm expecting more professionals here than in the iOS thread.

I feel like there are some thinking pattern traps that allow this to happen. One day I realized that it works like that with any software update. Once it's new and branded as "stability improvements", we feel like our software is super stable. Until there's next one - before we install that one, we feel like our previous one is no longer stable and we have bad quality software. But our software never changed! It's not like it got less stable over time. I hope you guys understand my point, because this shows the thinking patterns about hardware too. Many software requirements don't change, because this software remains the same, yet we are always pressured to replace our hardware, because if the new one is released, our becomes "obsolete". This is insane if you think about it. My favorite example are MacBooks, especially the jump from Intel to Apple Silicon. 16" Intel used to be considered a monster, until Apple Silicon came and 16" Intel became instantly "slow", even though the software we use was still the same.

Is anyone with me on that?

My macbook pro 15 inch from 2017 works better than ever under macOS ventura than it did with high Sierra, Mojave, Big sur.

If you’re pc is slower than it’s more likely user error. My MacBook Pro works better than ever 5+ years after owning it.

Every time I updated to a newer OS it was either faster or the same speed as before. Same goes for my iphone.


Don’t post misinformation please. You mentioned the battery thing and you essentially claimed that Apple was lying about that when in reality you’re the one who’s making things up now.

More likely you have apps that are not properly updated and they’re causing slowdowns.

 

[TBoneMac]

My evidence is my programming knowledge and my experience with Apple devices. My MacBook Air 2018 got significantly slower version by version. I hear complaints even from i9 owners. And it's been a decline even before Apple Silicon was a thing.

User errors exist (too many old apps that have not been updated, not enough storage space, viruses, people not taking care of their devices i.e. dropping/damaging them then blaming it on the new OS instead of their poor care)

my evidence is that my macbook and iphones have never got slower after updating and my 5+ year old macbook is faster than ever with Ventura.

Edit — not only is it faster (opens apps more quickly and surfs the web more swiftly) but it also runs cooler/plays games better.

(2017 MacBook Pro 15 inch)

 

[R3k]

Well, I assume that yardstick for optimizing software performance is generally based around whatever hardware is current generation.

As developers add features and complexities to their code, they tend to polish the performance so that it runs acceptably on current gen hardware

As hardware performance generally increases from generation to generation, then it makes sense that if a user just sits on the same computer, then over the years the software for it will perform slower, if said software is constantly in development.

Software devs eating up hardware performance gains so to speak = later versions of MacOS running slower on older computers than the MacOS it shipped with.

 

[BergerFan]

Not sure if it’s planned or not, but the supporting of older hardware for so long(whilst admirable), should end a bit sooner. My top-spec 2017 27” iMac now trundles through basic FCPX editing timelines on Ventura, when it never did previously, despite all the latest OS and app updates.

I wish I could roll back!

 

[Corefile]

Hard disks used to be bogged down when Snow Leopard came out and everything was slow. Then SSDs were a breath of fresh air as SL was suddenly fast. But over the releases SSDs now make the system as sluggish as hard disks in the old days. Back then an application could run in a few MB but then you add on the additional layers of junk for added indirection. We might have faster CPUs, faster memory, and fast IO, but SW will always find a way to chew that up to make it seem sluggish.

 

[FeliApple]

Well, I assume that yardstick for optimizing software performance is generally based around whatever hardware is current generation.

As developers add features and complexities to their code, they tend to polish the performance so that it runs acceptably on current gen hardware

As hardware performance generally increases from generation to generation, then it makes sense that if a user just sits on the same computer, then over the years the software for it will perform slower, if said software is constantly in development.

Software devs eating up hardware performance gains so to speak = later versions of MacOS running slower on older computers than the MacOS it shipped with.

I think this is the key. Apple optimises for the latest devices, both on iOS and MacOS. Therefore, older devices are obliterated.

Really, it’s been years. I think Apple users, sadly, have to accept this reality. On iOS you can stay behind, on MacOS you can go back.

If you don’t like that, you can update and (first slowly, then rapidly) see your device’s quality plummet. Fortunately Apple allows that choice. The day Apple forces every outdated device out of its original software version is the day I stop using Apple devices forever. So far, Apple allows it (iPhone Xʀ on iOS 12, iPad Air 5 on iPadOS 15, 2015 MacBook Pro 13” on OS X El Capitan).

 

[BigMcGuire]

My .02...

I've been using Windows since the early 90s and switched to Mac OS for my personal computing in 2015. I now use Mac OS for work since 2019 (but I have to run Windows on Parallels to do a lot of things - currently running W11).

I don't get it when people are surprised that companies are in business to make money. They expect companies to go out of their way to save them money but at the same time they, as a consumer, go out of their way to save every penny they can. We are all the same.

I've programmed (C#) for about a decade. I helped manage an iOS / Android app and it was astounding how much work had to go into the app, after it was developed, to keep it jiving with all the updates both Android and Apple threw at the OS - we were constantly getting notices that our app wasn't working because of XYZ security change. Yes, this is about Mac OS, I know just stating for the record.

Our usage is not the same right? 5 years ago I wasn't running 3 browsers with 10-20 tabs each, while Parallels ran Windows 11 with VS 2022 compiling a large project and doing a Teams video conference, sharing my screen with 20-30 people at the same time. 10 years ago I wasn't running apps that do half of what they do today. The interconnectivity we have between our devices today would shock my socks off 10 years ago. New features USE more resources.

I manage a team that includes a dev team, support team, documentation team, and training team. It's amazing the amount of $ and effort that goes into keeping an app maintained let alone optimized for the latest Windows version. I've worked this job since we compiled the app with Borland Builder C++. Our app now uses 10x the ram and CPU that it did back in the Borland Builder days, but it also has 10x the features, utilizes 10x the data, and interfaces with many other apps. Some of our customers are telling us how we don't do enough - they want us doing 10x more. Well guess what, that's going to use even more resources.

And yeah, anyone who thinks Mac OS is bad... I made a good living fixing Windows machines for companies and people I knew for decades as a side job. It is amazing what a simple disk wipe and OS reinstall does. Mac OS has been fairly stable for me all things compared. Companies would toss out TONS of old Windows machines that were crawling because they were loaded with tons of inefficient apps - a quick wipe and those machines were still very capable (but I wouldn't use them for business because they didn't get OS updates).


My opinion - the apps we use make the biggest difference. Most of the stuff I use today are bloated chromium web apps that use a gig of ram and tons of CPU just to do something a 3MB application did 10 years ago. lol. Any hardware churning through this load is going to seem a lot slower. Just moving my mouse over an MS Teams window uses a ton of CPU. lol.

 

[MacCheetah3]

There are multiple factors, including:

Our usage is not the same right? 5 years ago I wasn't running 3 browsers with 10-20 tabs each, while Parallels ran Windows 11 with VS 2022 compiling a large project and doing a Teams video conference, sharing my screen with 20-30 people at the same time. 10 years ago I wasn't running apps that do half of what they do today. The interconnectivity we have between our devices today would shock my socks off 10 years ago. New features USE more resources.

Extending on these:

• For video conferencing, we now have video effects that are both niceties, such as Portrait Mode, but also useful like Desk View:

Using the Ultra Wide camera, Desk View shows your desk and your face at the same time. It's great for creating DIY videos, showing sketches over FaceTime, and more.

And some that are both a nicety and helpful:

Studio light dims the background and illuminates your face, without relying on external lighting. Studio Light is great for difficult lighting situations, like backlit scenes in front of a window.

• The Photos (app) with face and environment recognition and well as the ability to auto organize and generate content (e.g., Memories slideshows).

• Synchronization of data among devices and remotely — which most users have expanded to including multiple services/sources for optimization and redundancy.

• Searches have widened immensely, sifting through many sources simultaneously with vastly more detail.

All of these conveniences require substantially more tasks working in tandem and concurrently, far more processing than the device was designed/expected to handle.

In addition...

Terms such as slow, fast, bad, and good are not only subjective, they’re perspective — “You don’t know what you’re missing.” For example:

• You’ve been happily snapping photos with your iPhone XS. However, recently, you acquired an iPhone 13 Pro. After experimenting with Macro and HDR recording, you realize you can capture more scenes, more lifelike with little extra effort.

Yes, I know this reads like marketing, but that’s because (non-fraudulent) marketing is encouragement (albeit oftentimes more aggressive than needed). Anyway….

Are these capabilities necessary? No. Does everyone care about this functionality? No. Does it improve quality of life/productivity? For some people, yes, and it has legit value.

One more thing...

I am still using my iPhone X as my primary portable device. While the runtime is noticeably less and some apps crash frequently when the charge level drops below 10%, browsing/searching the Web, scanning documents and converting them to PDF with Scanner Pro, sharing a snapshot or other image, managing my day (i.e., calendar and reminders), and more are accomplished without hassle.

Is the seemingly instantaneous OCR text recognition (again, Scanner Pro), smooth app switching or side-by-side app use, merely seconds wait for app updates and game app launches on the M1 iPad Pro more satisfying? Yes!

Am I intrigued to capture scenes with a much more capable camera system. Again, a strong ‘Yes!”

So, is having a recent generation/revision iDevice valuable? A third “Yes.”

The point being, companies don’t need to (nor probably) plan/design obsolescence, it’s (to their benefit) an effect of progress, including but not limited to the pursuit of convenience.

 

[MYZ]

Judging from Console logged errors and faults this might be possible, if inadvertently.

My 2019 macbook pro 15 i9 on MoJave gets about a couple hundreds errors every hour just sitting on the desktop after a fresh bootup, with Wifi, Bluetooth, and iCloud connected, and Activity Monitor open, but doing nothing else.

After upgrading to Monterey it got a couple hundred errors per MINUTE in the same scenario. And this happened even a few months later after updating...

When I downgraded back to Mojave it returned back to the previous state.

When there's literally 10x more or perhaps even 100x more of something, that's definitely going to cause some kind of slowdown.

 

[ignatius345]

I have an unpopular and perhaps a little controversial opinion that Apple makes old devices obsolete on purpose. Most people I talk about with about this disagree. Most people think that adding features to software makes it slower. I'm a programmer myself and I know this is not the case. Unless this feature works in the background, it has no impact on performance whatsoever.

I think the issue is that Apple is not really deprecating features on older hardware, and it takes a big toll on performance. I'm using an iPad here as an example because I'm facing this exact issue, but it 100% applies to Macs as well.

Here's a scenario: iPadOS 15 is being developed, and it's got more features than the previous version and needs more resources to run. Apple has users with iPad Mini 4s out there, so how do they handle it?

1) Impose a more restrictive cutoff, and stop that Mini at iPadOS 14 instead because 15 is going to be too demanding.
Result: Users get angry about how many years' support they are getting when they buy an iPad.

2) Let it rip. Ask the iPad Mini 4 to try to use the OS the same way a much newer iPad does. Responsiveness suffers, but the device technically runs the latest OS.
Result: Users get upset, but also conclude their iPad is "getting old/slow" and maybe they just replace it.

3) Simplify or dial back some of the more resource-intensive features of the OS when it's installed on an older iPad like this. The device remains responsive, hopefully, but maybe some stuff isn't available.
Result: users are confused about why their iPad doesn't support the latest iMessage reaction or multitasking feature, or whatever.

Speaking as someone whose iPad Mini 4 -- which was once very snappy -- is now super laggy and slow, I'd prefer #3. Take away a few features, tell me about it, and let me use the features that it's capable of running smoothly (and the latest security updates).

But #2, in addition to making Apple more money, also perpetuates the "latest and greatest hardware" narrative. Few people question the OS, they question their own device which has now been around for a few years and is no longer the new shiny thing. I think the average consumer just thinks it's "getting old" and slowing down the way your 10 year-old car might perform less well after you've put 200K miles on it. In reality, there's often no physical reason an older Apple device can't be as snappy and quick as it was when you bought it -- except for increasing demands of software.

 

[Zest28]

Show us some evidence to back up the claim. Don't get me wrong, we all know they have done it on other devices in the past but on macOS devices? Not seen any evidence to support that.

Windows on my old Intel MBP is as snappy as Mac OS on my M2 MBA.

And my 2010 MBP on Snow Leapord had the fastest shutdown time of any computer. It literally instantly shut down, even faster than a 16" M1 Max MacBook Pro on the current Mac OS.

 

[MYZ]

Windows on my old Intel MBP is as snappy as Mac OS on my M2 MBA.

And my 2010 MBP on Snow Leapord had the fastest shutdown time of any computer. It literally instantly shut down, even faster than a 16" M1 Max MacBook Pro on the current Mac OS.

Can you record a few second video of it shutting down? I think that would satisfy the parent commenter.

 

[DCBassman]

As an almost complete noob to the Apple world, and exclusively using "unsupported" hardware, I'm afraid I agree 100% with OP.
Every Mac I have here (four, 3 various iMacs and a Mac Pro) will run, say, High Sierra very happily indeed, even the two that are unsupported even for that. The Mac Pro, of course, has enough horsepower to run anything, with the right patching and graphics.
All these machines, as-is, will run any Linux effortlessly, even using spinning drives. And even better with SSDs.
The hardware in each is completely capable of running Windows 10 just fine, and Windows 11 with workarounds that are nothing to do with hardware capability.
None of the iMacs are capable of running anything beyond High Sierra without some fairly serious jiggery-pokery, either software or hardware, or both. For a quad-core i5 and 22GB of RAM to suffer at the hands of the OS is ridiculous, plain and simple. That specs eats any Windows or Linux for breakfast, easily. Why does MacOS impose such burdens on hardware? Answers on a postcard. It's just an OS, after all, there is nothing special about it in any fundamental way.
So, as well as making the hardware as unrepairable as they can get away with, the OS is constantly re-jigged to join in. It is always and only about what we in the UK call box-shifting. Move the product. Consequences? Who cares?

 

[DCBassman]

Having said that, any given machine will slow over time with the same OS on it, just through usage. This is much improved in these days of journalling and SSDs, but a well-used install is *always* slower than a fresh one, on the same hardware. The only way around that is to have a machine so over-powered that you can't slow it down...