Mendo

macplusplus said:

Mendo said:

Mike Wuerthele said:

Mendo said:

Tl;dr: It's not CPU/GPU power, it's a fixed RAM size, aging flash memory and increased memory footprints of iOS and apps that cause a perceived slowdown. And that simply can't be helped.

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This site regularly reports about hardware in a professional manner. So why in the world would an editor think that raw CPU/GPU power would matter? Of course changes to APIs happen over time that may impact the processing power directly in a minuscule way, but that is not where system slowdowns come from.

Performance issues are usually pretty much entirely memory-based. Flash memory is known to degrade over time, even with internal load balancing, so loading times naturally increase over time (far more noticeable than any change to raw CPU/GPU power could), but the real killer is memory management. The iPhone 6 plus has 1GB of RAM, compared to the 3GB of the 8 plus. iOS has grown steadily, and OS features always get priority when it comes to multitasking, so less availability memory for other apps. Meanwhile, apps also grow in size and functionality and need more memory, causing other running apps to get paged into the (constantly slowing) flash memory. So switching apps then causes a) running apps to be slowly written to flash, and b) the requested, hibernated app to be loaded from flash.

When I got my iPhone 6 plus almost 3 years ago, 1GB of RAM could comfortably hold several apps without having to swap any of it into a flash page file. These days my iPhone is often even struggling with loading on-demand parts of a running app into memory, and often even switching between two apps would cause either of them to reload, especially when it's memory hogs such a Facebook, Twitter and Chrome. Just switching between this holy trifecta can cause slowdowns that are less than pretty.

So what I, as a user, would expect from Apple and app developers, is better memory management for older phones, but even that can only do so much given that every app is constantly in a race of offering more and better looking functionality than its competitors, continuously bloating it's memory footprint up, and iOS obviously need to add features as well that can't be loaded on demand.

So what I'd really like to see is memory benchmarks and multitasking checks. Xcode for instance allows to at least see RAM usage. But for real comparisons, that would require old hardware with old iOS versions and old app versions to compare, and those are hard to come by.

Nope, that's not the case here. The iPhone's storage is over-provisioned, and there is no noticeable slowdown with time -- and even with heavy use over three years, you won't approach the limits of the read/write cycle.

https://imgur.com/a/fGsym (AnTuTu results)

Losses between 30-50% in general data i/o performance in comparison with a factory new model aren't exactly small.

Even with internal garbage collection, flash memory degrades. Overprovisioning can only do so much, and degradation is also highly depending on the base amount of memory available.

In combination with the increased memory appetite of apps across the board, that very well explains some of the performance issues quite a few users are seeing.

What you write about degradation of flash memory doesn't make sense. iOS has no swap file. The contents of RAM are not purged to the flash.

I’m gladly accepting alternative explanations for the performance drop that's visible in the benchmark. It should at least be fine to assume that apps can write a current state into their app data before purged from memory. Then there are serial offenders like the Spotify app that have already caused issues on desktop PCs/SSDs with their unorthodox caching behavior (now fixed there).

Whatever is causing it - again, up to 50% drop in flash i/o performance isn't small on any kind of scale.

Tl;dr: It's not CPU/GPU power, it's a fixed RAM size, aging flash memory and increased memory footprints of iOS and apps that cause a perceived slowdown. And that simply can't be helped.

############

This site regularly reports about hardware in a professional manner. So why in the world would an editor think that raw CPU/GPU power would matter? Of course changes to APIs happen over time that may impact the processing power directly in a minuscule way, but that is not where system slowdowns come from.

Performance issues are usually pretty much entirely memory-based. Flash memory is known to degrade over time, even with internal load balancing, so loading times naturally increase over time (far more noticeable than any change to raw CPU/GPU power could), but the real killer is memory management. The iPhone 6 plus has 1GB of RAM, compared to the 3GB of the 8 plus. iOS has grown steadily, and OS features always get priority when it comes to multitasking, so less availability memory for other apps. Meanwhile, apps also grow in size and functionality and need more memory, causing other running apps to get paged into the (constantly slowing) flash memory. So switching apps then causes a) running apps to be slowly written to flash, and b) the requested, hibernated app to be loaded from flash.

When I got my iPhone 6 plus almost 3 years ago, 1GB of RAM could comfortably hold several apps without having to swap any of it into a flash page file. These days my iPhone is often even struggling with loading on-demand parts of a running app into memory, and often even switching between two apps would cause either of them to reload, especially when it's memory hogs such a Facebook, Twitter and Chrome. Just switching between this holy trifecta can cause slowdowns that are less than pretty.

So what I, as a user, would expect from Apple and app developers, is better memory management for older phones, but even that can only do so much given that every app is constantly in a race of offering more and better looking functionality than its competitors, continuously bloating it's memory footprint up, and iOS obviously need to add features as well that can't be loaded on demand.

So what I'd really like to see is memory benchmarks and multitasking checks. Xcode for instance allows to at least see RAM usage. But for real comparisons, that would require old hardware with old iOS versions and old app versions to compare, and those are hard to come by.