iPad Pro With its 8 gbs of ram M1 expected life expectancy?

[Cattiy19]

That is exactly my decision problem. 2020 iPad pro 12.9 with 6 GB RAM vs 2021 iPad pro 11 with 8 GBs of RAM.
Screen size aside, i fear the 2021 11 inch with 8 GB Ram will age better? The 10.5 pro lasted me 4 years, and still is mostly fine with my use case and 4GB RAM.
But an improvement of only +2GB RAM from 2017 to 2020 iPad pro seems to small for me somehow for all this money.

The 2021 12.9 is not an option because of the prize and Mini LED and PWM.

 

[Digitalguy]

That is exactly my decision problem. 2020 iPad pro 12.9 with 6 GB RAM vs 2021 iPad pro 11 with 8 GBs of RAM.
Screen size aside, i fear the 2021 11 inch with 8 GB Ram will age better? The 10.5 pro lasted me 4 years, and still is mostly fine with my use case and 4GB RAM.
But an improvement of only +2GB RAM from 2017 to 2020 iPad pro seems to small for me somehow for all this money.

The 2021 12.9 is not an option because of the prize and Mini LED and PWM.

I think screen size consideration is more important than whichever ages better. They will still be fast and supported for many many years....

 

[rui no onna]

That is exactly my decision problem. 2020 iPad pro 12.9 with 6 GB RAM vs 2021 iPad pro 11 with 8 GBs of RAM.
Screen size aside, i fear the 2021 11 inch with 8 GB Ram will age better? The 10.5 pro lasted me 4 years, and still is mostly fine with my use case and 4GB RAM.
But an improvement of only +2GB RAM from 2017 to 2020 iPad pro seems to small for me somehow for all this money.

Exactly why I jumped from 2017 to 2021. The 2020 is a pretty minor refresh to the 2018 and the discounts I've seen aren't good enough.

 

[Adelphos33]

The only thing that would cause me to upgrade my M1 iPad ahead of 5 years would be if they moved the camera placement or something like that

 

[TraceyS/FL]

I don’t expect to be wanting to upgrade for a longgggg while. I upgraded from a 2017 12.9 that my boyfriend has claimed to go with his 2015 he bought used. Mr Android has been beyond happy with the iPad btw, which still cracks me up. Why does he need two??? (One will go on the booth for sales)

anyway, almost every iPad we’ve bought is still being used, I traded in one 1st gen and the Air 1. But we just shuffle them around. The Mini 1 my oldest has doesn’t get much use, she is getting the Mini5. My Dad is using the 9.75 pro - upgraded from iPad 2. My Mom will get the 6.

My procreate kid was having weird issues with her 10.5 she got last summer, so she got the M1 11 and sister that just media consumes will get the 10.5.

Basically the iPad is the best device for longevity I’ve ever used/owned. I’m sure Apple hates customers like me & mine, but it helps keep me as a customer too. I’m due a mac, but I’m not sure which to get…. But I’m a sucker for the green or orange. ?

 

[Homme]

Considering Apple is STILL supporting the first generation 12.9" iPad Pro and will continue to until AT LEAST fall of next year (at least seven years total), I'd say 6-10 years is likely. Even with 8GB of RAM on lower end M1 iPad Pros, they still are not allowing apps to fully continue to run in the background and each app is limited to 5GB. So, iPadOS isn't even utilizing the full 6GB of RAM that the 2020 A12Z iPad Pros had, let alone the 8GB of RAM that the 128-512GB M1 iPad Pro models have, let alone the 16GB of RAM that the 1-2TB M1 iPad Pro models have. It will be a good while.

I disagree. I think A9X iPads will get iPadOS 16. I doubt Apple will drop support of 2 generations of X Chips

plus both iPads are better than the A10 of the 7th Gen iPod Touch in terms of power (it’s A10 is severely underclocked and it’s weak battery compared to the iPads)

The only real difference in speed between the 2015 and 2016 pro, other than reloads, is that the 9.7 sometimes becomes unresponsive because of lack of RAM, but in normal use the difference is relatively small most of the time... In some demanding web pages (like youtube or gmail on Safari) it struggles (granted much less that something like the air 2 or the mini 4), while A10X with the same RAM is definitely faster and A12 even with only 3GB RAM is even faster than A10X and extremely fluid. At this point the CPU is more of a deciding factor than the RAM, and from 3GB and above RAM becomes a non issue for speed in 99% of situations. Things might change though in a few years...

A12 is better in single and multicore but even then the difference isn’t as huge (more multicore than single core)

longevity wise maybe A10X iPads and A12 with 3GB of RAM are in the same field

 

[Yebubbleman]

Given that ultra old iPads are still extremely useful and can do 90% of what the current gen iPads can do, I'd say you'll be good for a while.

I have a first generation iPad mini (A5) and a fourth generation iPad (A6X) that both beg to differ. As soon as an iPad gets left behind on iPadOS, things stop working right; especially if you have newer Apple products on current OSes. Furthermore you stop being able to run the latest versions of apps, which have varying degrees of impact on functionality (especially when the apps are connecting to and utilizing a service as their central function).

Note, the 5GB RAM per app limit is just for the 2021 iPP. The 2020 iPP has a limit somewhere around 4GB RAM while the 2017 and 2018 iPP is around 3GB. While a single app may be limited, the RAM does get fully utilized by the OS. Besides, the OS itself, GPU, etc. also need to use RAM.

Granted. But even then, we have Intel Macs with 4GB of RAM able to run macOS AND still have more than a single application open. We have Intel AND M1 Macs able to do the same with both 8GB and 16GB RAM capacities. The idea that only ONE app gets 5GB and the OS takes whatever is left over (which it honestly ought to not need all of) still equates to under-utilized RAM no matter how you slice it.

Honestly, I don't see how one can say 6GB RAM isn't being fully utilized when I'm getting reloads on that one and have seen free RAM drop to 100-200MB. That suggests to me there really isn't sufficient RAM available for background apps to use unless Apple implements swap ala-MacOS.

So what you're saying is that iPadOS isn't handling memory management anywhere near as efficiently as macOS. I get how swapping works. I'd think that the concept would make sense to employ on something like iPadOS, given that Apple wants me to consider it as my next dominant computing platform (over macOS and Windows).

With that said, I expect all flavors of the 2021 iPP will be supported for 6-10 years and support will be the same regardless if RAM is 8GB or 16GB.

Seeing as the 2018 iPad Pro had 4GB of RAM in all sub-1TB models and 6GB of RAM in 1TB models, I agree that it would be odd of them to put a mid-generation dividing line based on RAM. That being said, that has been the most common dividing line in the history of iOS/iPadOS. Hell, it's why A8/X iPads are still running the latest iPadOS version while A8 iPhones and iPod touches are not.

I think screen size consideration is more important than whichever ages better. They will still be fast and supported for many many years....

Respectfully, I disagree completely here. Certainly, the two sizes almost equate to two different experiences, but you pay extra for longevity and longevity isn't insignificant when it comes to a device that is eventually going to be discarded.

I disagree. I think A9X iPads will get iPadOS 16. I doubt Apple will drop support of 2 generations of X Chips

plus both iPads are better than the A10 of the 7th Gen iPod Touch in terms of power (it’s A10 is severely underclocked and it’s weak battery compared to the iPads)

For the record, I never said anything to contradict nor disagree with that. But neither of us knows what iPadOS 16's requirements will be whereas we do know iPadOS 15's and we know that A9X iPad Pros are at least along for that ride and that said ride is lasting until at least next fall. I didn't want to categorically assume A9X iPad Pros were going to still be supported because, for all I know, Apple could impose a different dividing line that has nothing to do with RAM. Certainly, I'd think that if they do limit out A9 based devices, but not all A9 devices, the first generation 12.9" iPad Pro, being the beefiest of them all, would still make the cut.

 

[rui no onna]

Granted. But even then, we have Intel Macs with 4GB of RAM able to run macOS AND still have more than a single application open. We have Intel AND M1 Macs able to do the same with both 8GB and 16GB RAM capacities. The idea that only ONE app gets 5GB and the OS takes whatever is left over (which it honestly ought to not need all of) still equates to under-utilized RAM no matter how you slice it.



So what you're saying is that iPadOS isn't handling memory management anywhere near as efficiently as macOS. I get how swapping works. I'd think that the concept would make sense to employ on something like iPadOS, given that Apple wants me to consider it as my next dominant computing platform (over macOS and Windows).

Maybe on 8GB+, RAM may be underutilized.

On 6GB and lower? My experience thus far says otherwise. If there were sufficient RAM, then apps/tabs wouldn't need to be ejected from memory. 4GB RAM works for Mac, Windows and Linux because there's swap. Of course, I've always been of the opinion that Apple's too stingy on RAM considering iOS/iPadOS doesn't have swap. I honestly hadn't expected that to change so color me surprised when the 2021 iPP was announced with 16GB on the high end.

I actually have been wishing for either swap support or large enough RAM so that swap isn't needed for my usage. The 2021 1TB actually gave me the latter albeit I bought it for storage.

Mind, 16-64GB base storage + swap would likely mean early SSD failures. Also, older SoCs had poor random 4K performance. If Apple ever does add swap to iPadOS, it would likely be limited to 2020 iPP at the earliest (faster SSD controller and 128GB base storage).

Seeing as the 2018 iPad Pro had 4GB of RAM in all sub-1TB models and 6GB of RAM in 1TB models, I agree that it would be odd of them to put a mid-generation dividing line based on RAM. That being said, that has been the most common dividing line in the history of iOS/iPadOS. Hell, it's why A8/X iPads are still running the latest iPadOS version while A8 iPhones and iPod touches are not.

The A8-based devices are still different models though. The 2018 and 2021 iPP would be the test cases whether Apple's gonna drop support on the same model based solely on RAM.

Mind, most common reason for dropping support has been chipset. I think there's only been like 3 occasions where it was RAM-based. Granted, RAM amount has been often tied to chipset.

 

[Homme]

I have a first generation iPad mini (A5) and a fourth generation iPad (A6X) that both beg to differ. As soon as an iPad gets left behind on iPadOS, things stop working right; especially if you have newer Apple products on current OSes. Furthermore you stop being able to run the latest versions of apps, which have varying degrees of impact on functionality (especially when the apps are connecting to and utilizing a service as their central function).



Granted. But even then, we have Intel Macs with 4GB of RAM able to run macOS AND still have more than a single application open. We have Intel AND M1 Macs able to do the same with both 8GB and 16GB RAM capacities. The idea that only ONE app gets 5GB and the OS takes whatever is left over (which it honestly ought to not need all of) still equates to under-utilized RAM no matter how you slice it.



So what you're saying is that iPadOS isn't handling memory management anywhere near as efficiently as macOS. I get how swapping works. I'd think that the concept would make sense to employ on something like iPadOS, given that Apple wants me to consider it as my next dominant computing platform (over macOS and Windows).



Seeing as the 2018 iPad Pro had 4GB of RAM in all sub-1TB models and 6GB of RAM in 1TB models, I agree that it would be odd of them to put a mid-generation dividing line based on RAM. That being said, that has been the most common dividing line in the history of iOS/iPadOS. Hell, it's why A8/X iPads are still running the latest iPadOS version while A8 iPhones and iPod touches are not.



Respectfully, I disagree completely here. Certainly, the two sizes almost equate to two different experiences, but you pay extra for longevity and longevity isn't insignificant when it comes to a device that is eventually going to be discarded.



For the record, I never said anything to contradict nor disagree with that. But neither of us knows what iPadOS 16's requirements will be whereas we do know iPadOS 15's and we know that A9X iPad Pros are at least along for that ride and that said ride is lasting until at least next fall. I didn't want to categorically assume A9X iPad Pros were going to still be supported because, for all I know, Apple could impose a different dividing line that has nothing to do with RAM. Certainly, I'd think that if they do limit out A9 based devices, but not all A9 devices, the first generation 12.9" iPad Pro, being the beefiest of them all, would still make the cut.

yeah it could be possible maybe just the 12.9 inch A9X Pro because of its 4GB of RAM but then it’s Geekbench 5 scores isn’t that different from A10 either. iPod Touch’s scores however are comparable to the A9 (A9’s clock speed is 1.85 GHz) and thats just the high performance cores

I do not know the requirements of iPadOS 16 but there are two factors I can share before WWDC Next Year 1. Apple TV HD Is discontinued since it has the same Chipset as Mini 4 and 2. 7th Gen iPod Touch is discontinued ( two iPod Touch’s in history got discontinued before WWDC and neither got the latest iOS Shown) . A wildcard is both SE and Touch being dropped because of they’re 4 inch screen ( more and more developers are whining about having to develop for that screen size)


with your quote to one of the members in respect to the “mod generation dividing line” ( I’m a bit confused) yes Air 2 and Mini 4 have iPadOS 15 because of they’re 2GB of RAM, but they were released in different times, iPad Mini 4 was only released a few months after Touch 6 did lol

 

[Yebubbleman]

yeah it could be possible maybe just the 12.9 inch A9X Pro because of its 4GB of RAM but then it’s Geekbench 5 scores isn’t that different from A10 either. iPod Touch’s scores however are comparable to the A9 (A9’s clock speed is 1.85 GHz) and thats just the high performance cores

That's assuming they have a dividing line based on raw performance, which they hardly ever do anymore.

I do not know the requirements of iPadOS 16 but there are two factors I can share before WWDC Next Year 1. Apple TV HD Is discontinued since it has the same Chipset as Mini 4 and 2

That sounds like a prediction, unless you have insider information to share...?

. 7th Gen iPod Touch is discontinued ( two iPod Touch’s in history got discontinued before WWDC and neither got the latest iOS Shown) . A wildcard is both SE and Touch being dropped because of they’re 4 inch screen ( more and more developers are whining about having to develop for that screen size)

I could see them trying to abandon the 4" size, but I don't know that it's a guaranteed definite, even if there is a precedent of Apple discontinuing an iPod touch mere weeks before announcing that the next iOS version won't run on it.

with your quote to one of the members in respect to the “mod generation dividing line” ( I’m a bit confused) yes Air 2 and Mini 4 have iPadOS 15 because of they’re 2GB of RAM, but they were released in different times, iPad Mini 4 was only released a few months after Touch 6 did lol

Release dates don't matter when it comes to this stuff. Apple drops support for products due to either RAM limitations or (as is much more commonly on the Intel Mac side of things) because a hardware feature is required across the OS and said hardware feature is not on the given SoC that they're dropping support for. The iPad Air 2 and the iPad mini 4 will lose support at the exact same time. Same for the fifth generation iPad and the iPhone 6s and 6s Plus. Apple drops support for SoCs more than they drop support for the devices that run them.

 

[Yebubbleman]

Maybe on 8GB+, RAM may be underutilized.

On 6GB and lower? My experience thus far says otherwise. If there were sufficient RAM, then apps/tabs wouldn't need to be ejected from memory. 4GB RAM works for Mac, Windows and Linux because there's swap. Of course, I've always been of the opinion that Apple's too stingy on RAM considering iOS/iPadOS doesn't have swap. I honestly hadn't expected that to change so color me surprised when the 2021 iPP was announced with 16GB on the high end.

Right. This all speaks to my point about RAM usage not being as efficient with iPadOS. They're treating it like iOS because that's where it's derived from originally. It makes sense to do these things on the phones (and you could also argue that it probably makes sense to do with the iPad mini due to the smaller size). It doesn't make sense on larger iPads, which are being positioned more and more as low-end computer replacements.

I actually have been wishing for either swap support or large enough RAM so that swap isn't needed for my usage. The 2021 1TB actually gave me the latter albeit I bought it for storage.

Mind, 16-64GB base storage + swap would likely mean early SSD failures. Also, older SoCs had poor random 4K performance. If Apple ever does add swap to iPadOS, it would likely be limited to 2020 iPP at the earliest (faster SSD controller and 128GB base storage).

You're not going to see any more SSD failures for an A14/M1 iPad than you would for an M1 Mac. I could see this being harder to implement for older devices (non-X and non-Z variant A12 and older, perhaps), but certainly not on any iPad with the current SoCs.

The A8-based devices are still different models though.

2GB of RAM on the A8X and the iPad mini's variant of A8; 1GB of RAM on the iPhone 6 and 6 Plus and 6th Generation iPod touch. Again, 2GB of RAM is still the dividing line which is why the former is running iPadOS 13-15 whereas the latter is not running past iOS 12.

The 2018 and 2021 iPP would be the test cases whether Apple's gonna drop support on the same model based solely on RAM.

Agreed. I don't believe that they'll allow 1TB 2018 iPad Pros, but disallow all others; it might just be simpler for them to just drop support for all of them all at once. The M1 models might be a different story; but with those, they may get dropped due to an as-of-yet unseen feature in a future SoC that becomes pivotal to a future iPadOS release.

Mind, most common reason for dropping support has been chipset. I think there's only been like 3 occasions where it was RAM-based. Granted, RAM amount has been often tied to chipset.

I'm pretty sure it's been RAM way more than three times. iOS 13, 10, 8, 7, 6, 5, and 3, I believe were all RAM related in the devices that didn't make the cut. Though you had A4 devices getting cut at three different times (first gen iPad being left out of iOS 6, fourth gen iPod touch being left out of iOS 7, and iPhone 4 being left out of iOS 8).

 

[Homme]

That's assuming they have a dividing line based on raw performance, which they hardly ever do anymore.



That sounds like a prediction, unless you have insider information to share...?



I could see them trying to abandon the 4" size, but I don't know that it's a guaranteed definite, even if there is a precedent of Apple discontinuing an iPod touch mere weeks before announcing that the next iOS version won't run on it.


Release dates don't matter when it comes to this stuff. Apple drops support for products due to either RAM limitations or (as is much more commonly on the Intel Mac side of things) because a hardware feature is required across the OS and said hardware feature is not on the given SoC that they're dropping support for. The iPad Air 2 and the iPad mini 4 will lose support at the exact same time. Same for the fifth generation iPad and the iPhone 6s and 6s Plus. Apple drops support for SoCs more than they drop support for the devices that run them.

I do not have any insider information to share but they are guesses from what I’m thinking

in fact Apple TV HD is the main reason why iPad Mini 4 is still having iPadOS 15. It’s a no brainer if that Apple TV is still sold in stores and will get tvOS 15 and if that got tvOS 15 then yes iPad Mini 4 got iPadOS 15 but many people didn’t see that part coming instead they believed in the ******** from iPhonesoft.fr and the verifier in which they’re predictions shouldn’t be believed ( and reported)

yeah who knows when they will abandon the 4 inch screen.

In history it’s slightly more CPU than RAM. Only 3 times in history that Apple dropped support because of RAM ( the 7 devices which have 1GB of RAM which couldn’t get iOS 13, Touch 4G and 3GS for iOS 7 and OG iPad for iOS 6). The thing is that there’s a lot of devices which have 2GB so I do not think the last 2GB device to be dropped ( iPhone 8) will be anytime soon so that Apple can focus on dropping support because of CPU ( as you outlined)?

 

[Homme]

Right. This all speaks to my point about RAM usage not being as efficient with iPadOS. They're treating it like iOS because that's where it's derived from originally. It makes sense to do these things on the phones (and you could also argue that it probably makes sense to do with the iPad mini due to the smaller size). It doesn't make sense on larger iPads, which are being positioned more and more as low-end computer replacements.



You're not going to see any more SSD failures for an A14/M1 iPad than you would for an M1 Mac. I could see this being harder to implement for older devices (non-X and non-Z variant A12 and older, perhaps), but certainly not on any iPad with the current SoCs.



2GB of RAM on the A8X and the iPad mini's variant of A8; 1GB of RAM on the iPhone 6 and 6 Plus and 6th Generation iPod touch. Again, 2GB of RAM is still the dividing line which is why the former is running iPadOS 13-15 whereas the latter is not running past iOS 12.



Agreed. I don't believe that they'll allow 1TB 2018 iPad Pros, but disallow all others; it might just be simpler for them to just drop support for all of them all at once. The M1 models might be a different story; but with those, they may get dropped due to an as-of-yet unseen feature in a future SoC that becomes pivotal to a future iPadOS release.


I'm pretty sure it's been RAM way more than three times. iOS 13, 10, 8, 7, 6, 5, and 3, I believe were all RAM related in the devices that didn't make the cut. Though you had A4 devices getting cut at three different times (first gen iPad being left out of iOS 6, fourth gen iPod touch being left out of iOS 7, and iPhone 4 being left out of iOS 8).

only iOS 13, 7 and 6 was because of RAM.

iOS 10 all 512MB devices got dropped but also A5X which has 1GB of RAM got dropped as well so definitely CPU, iOS 8 dropped iPhone 4 because of CPU,

Touch 2G and iPhone 3G didn’t even get iOS 4.3 let alone 5, but the real reason they got dropped was because of the iPhone 3G’s CPU and how that ran iOS 4.0

i do not know why you put iPhoneOS 3 when all devices which ran 2.0 got 3.0

 

[Yebubbleman]

only iOS 13, 7 and 6 was because of RAM.

iOS 10 all 512MB devices got dropped but also A5X which has 1GB of RAM got dropped as well so definitely CPU, iOS 8 dropped iPhone 4 because of CPU,

10 still technically dropped devices due to low RAM. The A5X was also a total joke.

Touch 2G and iPhone 3G didn’t even get iOS 4.3 let alone 5, but the real reason they got dropped was because of the iPhone 3G’s CPU and how that ran iOS 4.0

i do not know why you put iPhoneOS 3 when all devices which ran 2.0 got 3.0

I meant 4. You're right in that 3 didn't drop support for anything.

 

[Homme]

10 still technically dropped devices due to low RAM. The A5X was also a total joke.

I meant 4. You're right in that 3 didn't drop support for anything.

yes 10 dropped all 512MB devices but then Apple wanted to drop support of the A5 lineup entirely which yes included the joke which is the A5X

with iOS 4 iPhone 2G and First Gen iPod Touch has the exact same CPU/RAM as iPhone 3G so they weren’t dropped off because of RAM or CPU. They were dropped off because they weren’t as new as iPhone 3G was at the time ( and they were lucky not to get iOS 4)

 

[Digitalguy]

I disagree. I think A9X iPads will get iPadOS 16. I doubt Apple will drop support of 2 generations of X Chips

plus both iPads are better than the A10 of the 7th Gen iPod Touch in terms of power (it’s A10 is severely underclocked and it’s weak battery compared to the iPads)






A12 is better in single and multicore but even then the difference isn’t as huge (more multicore than single core)

longevity wise maybe A10X iPads and A12 with 3GB of RAM are in the same field

Not huge, just as A10X is not huge over A9X, but in both cases definitely noticeable.
And I tend to agree, they could have the same support (many years from now)

 

[Digitalguy]

Respectfully, I disagree completely here. Certainly, the two sizes almost equate to two different experiences, but you pay extra for longevity and longevity isn't insignificant when it comes to a device that is eventually going to be discarded.

Let’s agree to disagree on this…

 

[Digitalguy]

So what you're saying is that iPadOS isn't handling memory management anywhere near as efficiently as macOS. I get how swapping works. I'd think that the concept would make sense to employ on something like iPadOS, given that Apple wants me to consider it as my next dominant computing platform (over macOS and Windows).

I don’t think that having virtual memory (swap) equates to managing memory more efficiently, it’s 2 different things. Regardless, Apple doesn‘t want anyone to consider iPad as the dominant computing platform over MacOS. That’s nothing more than the interpretation from some people on these forums of some Apple‘s ads, which can and probably should be interpreted in a totally different way.
Apple has shown clearly that they want people to have both a Mac and an iPad (and if possible some expensive accessories too)

 

[SteveManila1960]

Depends on the use case. Feather weight user, don't need the latest greatest for any reason. Using 2015 MBA with 4GB RAM if I had an M1 MBA with 8GB RAM probably 10 years.

 

[rui no onna]

You're not going to see any more SSD failures for an A14/M1 iPad than you would for an M1 Mac. I could see this being harder to implement for older devices (non-X and non-Z variant A12 and older, perhaps), but certainly not on any iPad with the current SoCs.

NAND endurance is partly based on capacity. A 64GB iPad Air 4 would have 1/4 the endurance of a 256GB M1 MacBook Air.

2GB of RAM on the A8X and the iPad mini's variant of A8; 1GB of RAM on the iPhone 6 and 6 Plus and 6th Generation iPod touch. Again, 2GB of RAM is still the dividing line which is why the former is running iPadOS 13-15 whereas the latter is not running past iOS 12.



Agreed. I don't believe that they'll allow 1TB 2018 iPad Pros, but disallow all others; it might just be simpler for them to just drop support for all of them all at once. The M1 models might be a different story; but with those, they may get dropped due to an as-of-yet unseen feature in a future SoC that becomes pivotal to a future iPadOS release.


I'm pretty sure it's been RAM way more than three times. iOS 13, 10, 8, 7, 6, 5, and 3, I believe were all RAM related in the devices that didn't make the cut. Though you had A4 devices getting cut at three different times (first gen iPad being left out of iOS 6, fourth gen iPod touch being left out of iOS 7, and iPhone 4 being left out of iOS 8).

iOS 10 was definitely chipset based. Case in point:

iPad 3 1GB RAM: dropped
iPad 4 1GB RAM: supported
iPad Air 1GB RAM: supported


iOS 4 was likely just age-based considering the OG and 3G used the same CPU.

OG iPhone 128MB RAM: dropped
iPhone 3G 128MB RAM: supported

Really, Apple mostly drops support based either on age or overall performance. It just so happens a chipset upgrade is often accompanied with a RAM upgrade as well particularly during the early days.

 

[perezr10]

My 2017 iPad Pro lasted me 4 years so I voted 4-6.

And from a performance standpoint, it’s still very capable. I just got to the point where I wanted the slightly larger screen, FaceID, and the much nicer Apple Pencil.