Apple slows your iPhone down "to conserve battery"

Status
Not open for further replies.
I don't see anyone else doing this so it raises a lot of questions, if it's just Apple then is it the case their batteries degrade faster? If so why? increased load or quality issue?

Or is it because the capacity is generally quite low in comparison so the effect is a lot more noticeable? they even mentioned batteries shutting down which is quite alarming.
 
Anyone with half a brain can see this is a ruse to sell more iPhones.

If your phone has got to two years old and the battery is starting to wear and your phone is slow, you are likely to just replace it.

If you knew a replacement battery would also restore the performance, you'd be more inclined to go down this route.

Pretty deplorable from Apple.
 
People are making it seem like an iphone that is a few years old is so slow that its unusable. Reality is that this decision really extends the life of the phone for most. A phone is SIGNIFICANTLY less useful if you do not have the battery to keep it on all the time. A slow phone may be annoying at times, but its not like its functionality goes out of the window.

Imagine if they did nothing to extend battery life, people would be complaining about manufacturers putting crap batteries in, forcing people to buy new phones.

But it's not extending battery life. There's no such thing as magic.

The calculation which the CPU needs to perform remains EXACTLY the same.

When you reduce CPU speed, it simply needs to work longer to perform the same calculation.
 
You don't just magically half the workload just by halving the CPU speed. The workload remains the same.

drunkenmaster explained this in post 65.
 
I can't see the issue. I bet that 90% of the people moaning in this thread are android supporters.

Yes, your phone slows down. But the upshot of that is that your battery life is unaffected. If you had a choice, you might well accept that off the bat.

I do agree, though, that we should have been made aware of this. I would much rather replace my battery than keep replacing my phone.
 
They may have to go through the same work load but fact is that the battery is under less stress. Due to the processor being throttled, the phone does not reach the same temperatures as it would do when working at full speed. If the work load is the same but processing power is less, then it has a longer amount of time to dissipate heat produced while processing the work load.

I certainly have had old phones in the past get to the point when they needed to emergency shut down due to heat. Near these temperatures battery life can be significantly effected.

Also, it wasn't like people have not been aware that old phones feel slower. I very much doubt that this new revelation will convince someone to switch brand or snub the next phone.
 
People are making it seem like an iphone that is a few years old is so slow that its unusable. Reality is that this decision really extends the life of the phone for most. A phone is SIGNIFICANTLY less useful if you do not have the battery to keep it on all the time. A slow phone may be annoying at times, but its not like its functionality goes out of the window.

Imagine if they did nothing to extend battery life, people would be complaining about manufacturers putting crap batteries in, forcing people to buy new phones.

Slowing the cpu down DECREASES battery life. Hurry up and slow down, even Intel eventually learned this and Atom became slightly less bad in mobile devices. When you slow down the cpu you increase the time the CPU is on, and the time the uncore is powered and the I/O and constantly refresh memory, etc. Getting the work done quicker then shutting down as much power as possible is significantly more effective, most of the industry tried the slowest clock speeds/voltage/power and you got laggy devices that weren't efficient, everyone moved to hurry up and slow down, every chip is now massively more optimised for higher clock speeds making running lower clock speeds even less efficient than on the older designs at least optimised for lowest clock speeds. Cutting cpu performance in half will compound the problem of decreasing battery life by reducing it even further, causing further recharging and on and on.

Improving battery life would be optimising the OS for older devices and reducing CPU cycles required, adding features only for newer more powerful CPUs rather than adding features which take more cycles on their older devices.

What Apple is doing is compounding and worsening the effect and giving the customers less reason to simply replace the battery.

Scenario for most other phone companies, battery life reduces but performance is still great, you can send your phone in for £70 to get a new battery from somewhere and then you get your phone with it's great performance. With Apple, not only is your battery life reducing, it's not reducing faster, performance is halved, you have no idea why your device is suddenly really laggy so rather than simply think the battery is dying you think maybe the phone is, now that £70 seems like you might be throwing money away by replacing the battery on a dying device. You don't know that the new battery will restore performance and so you think it's a waste and are instead more likely to upgrade.

A slower phone is worse in every way for battery life.
 
Slowing the cpu down DECREASES battery life. Hurry up and slow down, even Intel eventually learned this and Atom became slightly less bad in mobile devices. When you slow down the cpu you increase the time the CPU is on, and the time the uncore is powered and the I/O and constantly refresh memory, etc. Getting the work done quicker then shutting down as much power as possible is significantly more effective, most of the industry tried the slowest clock speeds/voltage/power and you got laggy devices that weren't efficient, everyone moved to hurry up and slow down, every chip is now massively more optimised for higher clock speeds making running lower clock speeds even less efficient than on the older designs at least optimised for lowest clock speeds. Cutting cpu performance in half will compound the problem of decreasing battery life by reducing it even further, causing further recharging and on and on.

Improving battery life would be optimising the OS for older devices and reducing CPU cycles required, adding features only for newer more powerful CPUs rather than adding features which take more cycles on their older devices.

What Apple is doing is compounding and worsening the effect and giving the customers less reason to simply replace the battery.

Scenario for most other phone companies, battery life reduces but performance is still great, you can send your phone in for £70 to get a new battery from somewhere and then you get your phone with it's great performance. With Apple, not only is your battery life reducing, it's not reducing faster, performance is halved, you have no idea why your device is suddenly really laggy so rather than simply think the battery is dying you think maybe the phone is, now that £70 seems like you might be throwing money away by replacing the battery on a dying device. You don't know that the new battery will restore performance and so you think it's a waste and are instead more likely to upgrade.

A slower phone is worse in every way for battery life.

Not sure I agree with this - have you got any evidence?

I don't think that large spikes (peaks and troughs) in power consumption are more efficient than sustained, consistent power usage.

What about CPU throttling in PCs? Low power mode in my microserver seems to limit the CPU speed rather than letting it jump up and down.

Even driving - you use less fuel by driving more consistently rather than harsh acceleration and sudden braking.
 
They may have to go through the same work load but fact is that the battery is under less stress. Due to the processor being throttled, the phone does not reach the same temperatures as it would do when working at full speed. If the work load is the same but processing power is less, then it has a longer amount of time to dissipate heat produced while processing the work load.

I certainly have had old phones in the past get to the point when they needed to emergency shut down due to heat. Near these temperatures battery life can be significantly effected.

Also, it wasn't like people have not been aware that old phones feel slower. I very much doubt that this new revelation will convince someone to switch brand or snub the next phone.

This is all pretty much nonsense, a phone shutting down to overheating is a faulty phone, not an average use case. If you heavily benchmarked a fresh iPhone you'd get sustainable repeatable scores. 2 years later you do the same tests and people are literally showing half the performance then sending phone off for new battery, same phone coming back and getting the original score. We're not talking about unsustainable clock speeds, we're talking about the exact same user cases. Also battery life is down universally, most people don't run benchmarks, most people have zero overheating issues because we're talking about checking e-mails, loading a webpage, making a call and listening to some music. Regardless of the workload halving performance means everything takes longer, the chip is on for longer. Where the efficiency comes in is turning on the phone to check for e-mail and going to full power for 0.3 seconds then powering down, then powering up again for another 0.2 seconds, then turning the phone back off, when the performance is halved it's staying on for twice as long and burning a lot more power to do it. That is where 90% of everyone's power goes, the throughout the day tiny bits of power used for small loads, not constant benchmarking and heavy temp situations. But again even benchmarking we're talking about sustainable loads, not overheating or shutting down devices and the exact same benchmarks being run with half the performance two years later. Normal users who do nothing strenuous are getting significantly reduced performance and battery life.

My crappy little Moto G 4G I ran benchmarks on the other day just to check where it was vs the replacement phones I'm looking at and the scores are exactly where a meh Snapdragon 400 should be performance wise. The battery life has degraded over time and yet I still get full performance and the overall feel of the phone is about the same. It's a bit slower as applications demand more power over time but it's essentially the same experience and real benchmarks give the expected performance.

I'd be mad as hell if they advertised X performance but really they delivered X - (Y x time) performance.
 
Not sure I agree with this - have you got any evidence?

I don't think that large spikes (peaks and troughs) in power consumption are more efficient than sustained, consistent power usage.

What about CPU throttling in PCs? Low power mode limits the CPU speed rather than letting it jump up.

Even driving - you use less fuel by driving more consistently rather than harsh acceleration and sudden braking.

Gas engines aren't in any way comparable to silicon chips, just absolutely nothing in common at all. The entire industry in mobile moved to the hurry up and slow down model, everyone who didn't (Intel) got left behind and then adopted it themselves.

In terms of engines, to get up to speed a car has to overcome inertia and accelerate the car then it can use less power to just maintain that speed, it's literally doing completely different levels of work. If anything you can consider accelerating up to speed 'load' for a cpu and maintaining speed 'idle', or the lower power state. So in that scenario the idea would be the quicker you can get to the lower power using maintaining speed state, the more efficient your overall trip would be. Or the quicker you accelerate from 0-70mph the sooner you can drop power and maintain 70mph. You're just thinking about it backwards.

With cpus though there is no inertia, it doesn't take more effort or time to accelerate to 1.5Ghz over 750Mhz, it's just instant torque as with an electric engine, you just pick a clock speed and go.
 
A slower phone is worse in every way for battery life.

Intel are limited by the fact that they only make hardware. Apple design everything from the CPU to the operating system to the core apps used on their phones. They can do the kind of joined-up thinking that’s impossible for Intel.

Not all tasks require a fixed amount of calculations. For example, PC games offer a range of graphical settings. Apple have the ability to drop or simplify tasks for slower CPUs.
 
Gas engines aren't in any way comparable to silicon chips, just absolutely nothing in common at all. The entire industry in mobile moved to the hurry up and slow down model, everyone who didn't (Intel) got left behind and then adopted it themselves.

In terms of engines, to get up to speed a car has to overcome inertia and accelerate the car then it can use less power to just maintain that speed, it's literally doing completely different levels of work. If anything you can consider accelerating up to speed 'load' for a cpu and maintaining speed 'idle', or the lower power state. So in that scenario the idea would be the quicker you can get to the lower power using maintaining speed state, the more efficient your overall trip would be. Or the quicker you accelerate from 0-70mph the sooner you can drop power and maintain 70mph. You're just thinking about it backwards.

With cpus though there is no inertia, it doesn't take more effort or time to accelerate to 1.5Ghz over 750Mhz, it's just instant torque as with an electric engine, you just pick a clock speed and go.

Just an example with the ICE really, I know its not directly comparable. Take my HP Microserver. When you set low power mode in the BIOS is limits CPU speed for guaranteed lower power usage. Why would they do that if lower power usage could be achieved and guaranteed by peaks and troughs based on usage? Because you can't.

You can't assume a user isn't going to run a CPU intensive task like a game on their phone for hours maxing out the CPU (and if it wasn't throttled, it would draw significantly more power) and annihilating their already degraded battery. From a user perspective, the 'time' is directly related to how long they can use their phone, not necessarily how long the CPU takes to complete a task.

It's therefore a safer assumption to apply a 'general use' case as it is the more consistent, safer approach.
 
Not sure I agree with this - have you got any evidence?

I don't think that large spikes (peaks and troughs) in power consumption are more efficient than sustained, consistent power usage.

What about CPU throttling in PCs? Low power mode in my microserver seems to limit the CPU speed rather than letting it jump up and down.

Even driving - you use less fuel by driving more consistently rather than harsh acceleration and sudden braking.
With a computer (or related device) to do work with the CPU and GPU requires large parts of the system to be "up" and running at higher speeds, with a mobile phone that will likely include the display (you're likely to be actually using it when the CPU isn't at idle).

That means that you may be saving a bit of power by throttling the CPU but you're unlikely to be saving much/any power on any of the secondary parts of the phone (memory, storage, display, wireless communications), so by halving the processor speed you're not doubling the amount of time the phone will last between charges when under load, as those other major parts will still be consuming power at the same rate.

Probably a better way (from a pure power consumption point of view and conserving the battery) would be for the display to halve in brightness, that way the CPU is running for less total time and at a lower total power consumption, but it would be immediately obvious and make the phone less usable.

A PC that has throttled itself to lower power modes will also likely be turning off things like hard drives that aren't in use and haven't been accessed for X minutes.

I'm guessing the reason Apple seem to be having this problem when it doesn't seem some of the other phone manufacturers are, will be down to the choice of battery design and power regulator - they mention the battery not being able to provide enough power when it's aged for full load resulting in shut downs, that suggests to me that the battery design is such that it isn't able to provide the current the chip that regulates the power needs*, or that chip isn't able to handle the situation as well as it should.



*The whole idea of a power regulator chip is to keep a steady output voltage and current regardless of the input voltage within the design range of that specific chip.
 
I dont think it's quite as simple as the limiting of clockspeed. Take the last gen Apple A10 (the A11 is similar, just more of everything), it's basically a Big.little 4x core architecture and it has two high performance / high power usage cores and two slower more efficient cores. if apple are limiting clockspeed over time to compensate for battery capacity loss, then I would assume that the byproduct of that is less work being done on the high power cores and more being shifted to the lower power cores.
 
drunkenmaster knows what he's talking about.


What I don't understand is why don't they simply accomplish this using screen brightness.

Android has this feature when you put the screen above 80% it warns you that it will be using too much battery.

They could have simply limited the screen brightness. Less photons being ejected from the screen does certainly equate to less energy usage. This nonsense with limiting CPU performance which means it has to work longer to perform the same task is just nonsense.
 
Got a 6S and my battery is still performing amazingly well.

If you have an iPhone it’s not like you can’t afford to replace it anyway.

Storm in a tea cup.
 
Status
Not open for further replies.
Back
Top Bottom