Both my iPad & iPhone CPUs are being throttled

Question

Level 1

8 points

Both my iPad & iPhone CPUs are being throttled

I'm on OS 13.3.1 on an iPad & iPhone both bought in late 2017. In the last few months, I've noticed performance has fallen dramatically. In my music making apps, I can't play back songs, that ran with zero problems just a few weeks ago. Even basic everyday activities like installing an app now takes 10 minutes or more. Half the time, I can't even type because it hangs and stops responding.

I ran Geekbench 5 on both devices and its reporting anywhere from 1/4 to 1/3 of the speed similar devices (same year & model) that have been reported by other users.

I tried speaking with support via chat and I was told that it was a battery issue. They suggested I pay for a battery replacement but the OS doesn't show there's anything wrong. Also everything I've read claims there is no CPU throttling on iPads. The suspicious part is that this is happening on two different devices.

Is this a known issue with a bugfix in the works? Right now these devices are almost useless to me.. I'd be really upset if this doesn't get fixed soon, these devices are less then 3 years old.. that's an unacceptably short life for such an expensive device.

Posted on Mar 16, 2020 7:57 AM

Reply

Answer 1

LotusPilot

Level 10

302,546 points

Mar 16, 2020 9:30 AM in response to dustyny1

Okay - you are clearly a “notch-above” our typical community members in your understanding of the technicalities. Now that we’ve established appropriate levels for both vocabulary and competence, lets move on.

Agreed, on the basis of your report, something may well be going on. The suggestion that both your iPhone and iPad share similar performance issues, given that whist the system architectures are similar but utilise different CPU/GPU and other components, might suggest that the problem is not hardware per-se; perhaps you should look toward commonality in use of third-party Apps. This may require systematic deletion of Apps and subsequent performance measurement.

An additional App that you might find useful in diagnosing any performance issues is System Status Pro: hw monitor - available from the App Store:

https://apps.apple.com/gb/app/https://support.apple.com/en-us/HT204184

In context of finding a resolution, you may be best advised to first follow the basic and simple escalation route of restart, reset, reinstall:

1) Perform a forced-restart of affected devices:

https://support.apple.com/en-gb/guide/ipad/ipad63d30b5a/ipados

2) If a forced-restart is not successful, reset your device settings to default settings:

Settings > General > Reset > Reset All Settings. Avoid Erase All Content & Settings

3) If still experiencing performance issues, ensure that you a recent iCloud or iTunes Backup - then follow the procedure to Restore your device. This will reset your device and install a fresh copy of the latest supported version of iOS/iPadOS - and optionally restore your device data from the iCloud/iTunes backup.

https://support.apple.com/en-gb/HT201252

https://support.apple.com/en-us/HT204184

You might choose to follow the Restore process twice - the first time electing to dispense with data restoration from backup and running any performance measurements that you choose; this will establish a performance baseline against which comparison may be made. For the second restoration attempt, restore your data from backup, then repeat any performance measurements.

Hopefully the restore process will resolve any lingering issues.

Reply

Answer 2

dustyny1 Author

Level 1

8 points

Mar 16, 2020 9:07 AM in response to LotusPilot

LotusPilot,

Thanks for taking the time to explain. :)

I have a pretty good understanding of battery tech. I might not practice it anymore but my first degree was in electrical engineering.

I agree peak battery output has dropped a little. My phone shows battery maximum capacity at 88%, which is a 12% reduction. Now of course battery tech isn't always linear, so we can imagine that I'd see more than 12% reduction in this system. We can compound that by saying CPU/GPUs need specific power requirements to operate at different performance modes and that is usually tied to a divisor. No need to go down that rabbit hole for this convo.

Even with all of that generosity, a 66-75% performance reduction is disproportionally large. Worse yet, I'm not being notified in anyway that this has occurred and I have no way to disable it.

Another issue with this thinking is the problem persists when plugged in to an external power source. Now that could be a physical architecture issue but that seems like a business decision not an engineering one. I have plenty of devices (low and high end) that were totally unusable on battery power but work perfectly when plugged in to the wall. I would be 100% fine with using my iPad plugged in, thats how to work most of the time anyway..

Lastly as you pointed out these are two very different devices. The iPad has a much larger battery, though the other components are the same. So the chances of these happening at the same time should be much lower, the larger battery in the iPad should delay the onset of throttling. This happened after one of the updates which feels like they either pushed out a bug or made a change to the power management logic that is way too aggressive.

Reply

Answer 3

LotusPilot

Level 10

302,546 points

Mar 17, 2020 4:49 PM in response to dustyny1

After a major version update - or following a system restore - performance will appear to suffer for a few days as the system must re-index as a background task. Performance should settle at its true value after a few days of use.

Reply

Answer 4

dustyny1 Author

Level 1

8 points

Mar 17, 2020 4:28 PM in response to LotusPilot

I had done all the other stuff before, first things I tried.. The only thing I didn't do was a full wipe..

Ironically, I wiped my phone and it got worse. With a full charge (as I can get) and only Geek bench & the app above installed, I'm now seeing 100 points lower performance in benchmarks.

Doesn't look like problem with my configuration/profile

Reply

Answer 5

dustyny1 Author

Level 1

8 points

Mar 17, 2020 4:52 PM in response to LotusPilot

I can see how some background setup jobs could eat up a little CPU.. Taking that in to account, no change. I'm still throttled

Reply

Answer 6

LotusPilot

Level 10

302,546 points

Mar 16, 2020 8:26 AM in response to dustyny1

How long you have had your iPad and iPhone is, to a large extent, irrelevant. Battery lifespan is determined by the number of full charge/discharge cycles over the period that you have been using the device - and your charging habits. One full charge cycle is defined as a total of 100% - which may be achieved in any combination of charge cycles - e.g., 2 x 50%, 10% + 90%, 30% + 70% etc.).

iPhone is quoted as having a battery lifespan of 500 full cycles - with a residual capacity of 80% of that when it was new. By contrast, iPad is quoted as 1000 full cycles retaining 80% of its capacity from new.

Additionally, batteries degrade over their useful lifespan - and their ability to provide peak-current under demanding CPU load diminishes through use. It is for this reason that iPhone (not iPad) throttles its peak CPU load - such that the battery can provide adequate power without crashing the CPU.

Apple have not, to my knowledge, confirmed that iPad performance is managed per iPhone. You should consider that iPad batteries are considerably larger (with much greater capacity) than iPhone - and the challenges of maintaining peak performance are somewhat easier with larger batteries.

”Typical” battery life prior to needing a new battery (whatever “typical” actually means) is often quoted for a phone to be two (2) years for a device used and charged daily - but this is obviously highly dependent upon individual usage patterns. It is my understanding that iPad battery life is expected to somewhat longer, many expressing this is the region of five (5) years. As such, if you use your iPhone in a way that matches the “norm” perhaps you are overdue a battery change; your iPad might be approaching that point.

Consider also that if running iPadOS, due to much higher system demands, significantly greater load is being placed upon your iPad battery. My own systematic testing and measurement suggests that iPad Pro is routinely achieving battery use, prior to requiring recharge, of about 80% of that achieved with iOS 12.x.

I hope you find this information to be of some help in understanding the performance and limitations of your devices and their batteries.

Reply