Why is ATH.exe using 50% of my CPU?

Well,

I don't believe you can be as strongly worded as for "meaningless".

My system used to show this symptom after only 1 hour tops. I have now running for over 24 and it is doing fine.

I'm optimistic by nature. That counts as a very positive sign.

On the other hand, I can even say 72 h not yet enough (ie. meaningless) just because somebody that we don't knwo about experiences this after 120h...

Confirming that sync over wi-fi is still just as broken as it has been since Apple wrecked it in iTunes 10.7. Once I've restarted Apple Mobile Device service, I have maybe a 10 minute window to sync my iPad 3 and iPhone 4. After 10 minutes, forget it, iTunes won’t find my devices and I'll have to restart the service and iTunes.

I see no indication Apple is even looking into this matter so we might as well just settle for USB plugs and stop worrying about it.

With this and an accumulation of other iOS annoyances, I've decided that I’m done trying to adapt my computing life to Apple's idea of the future. No need to since Android has matured. Apple once dominated with features and user experience but that’s far from true nowadays. Personally, I'm due for a new phone. It will be an Android and I'm looking forward to uninstalling iTunes and never looking back. Spotify and Google won me over while Apple was sleeping on its laurels.

I'm giving the combination of iPhone 4S 64GB (15 months old) with iOS 7 and iTunes 11 (both installed two days ago) a cautious thumbs up. After installing both, re-enabling WiFi sync, and rebooting the computer two days ago I have been monitoring the behavior of ATH.exe, even during a WiFi sync, and it is not showing any increase in either CPU or memory usage.

If this holds for another day or two or if it starts acting as before, I'll come back and report here.

*keeping fingers crossed*

I have "TuneSync" to synchronise my Android tablet with iTunes. Never had a problem with it. Five minutes of iTunes wifi sync and the problem starts.

So... I can wifi sync Apple iTunes with an Android phone, but not an iPhone...

Good sales technique there, Apple.

May I suggest that those who report on their experience add information about their configuration? We could then probably see which configurations pose more problems and which ones seem to work better.

iPhone Model:

iOS Version:

iTunes Version:

WiFi Sync:

Windows Version:

Experience:

For example, mine is as follows:

iPhone Model: 4S 64 GB (MD258D/A)

iOS Version: 7.0 (11A465) - installed 20 Sept 2013

iTunes Version: 11.1.0.126 - installed 20 Sept 2013

WiFi Sync: enabled - 20 Sept 2013

Windows Version: Windows 7 Professional - rebooted 20 Sept 2013

Experience: 48 hours running so far without CPU/memory problem

Has worked for about week now, first time ever. No CPU issues.

iPhone Model: 5 16 GB

iOS Version: 7.0

iTunes Version: 11.1

WiFi Sync: enabled

Windows Version: Windows 8.1 Preview

Experience: About a week running so far without CPU/memory problem. Has synced almost everynight when I plugged in, 1 didn't for some reason.

Update:

5 days 15 hours since reboot without CPU/memory problems.

ATH.exe running smoothly at 0% of CPU and 5.4 K Memory.

iPhone Model: 4S

iOS Version: 7.0

iTunes Version: 11.1.0.126

WiFi Sync: enabled

Windows Version: Windows 7 Pro

OK, I'm cautiously optimistic. I upgraded to iTunes 11 and iOS 7 when they became available to me, so what, a couple of weeks? The first day I kept the PC and iTunes running for over 24 hours which is something I usually don't do. iPhone and iPad too. Since then I've synched my iPad 2 via wireless and my iPhone 4S via USB (the method I usually use) every other day. I've left iTunes running to try to reproduce the problem by taking the iPhone out of range of the wireless while iTunes was running and then returning it to coverage. This would cause AppleMobileDeviceService.exe to run at 25% CPU 90% of the time and ATH.exe would do the same approximately 75% of the time too.

Since upgrading these two processes appear to be running normally and neither has started hogging 25% CPU occupancy as they did before.

Additionally my iPad has been recognized and synched via wireless every time without error. That has never happened before. My iPhone however still intermittently synchs via wireless generating the usual errors. I typically only synch when I charge so that's not a major issue for me but I won't say that everything is fixed with respect to wireless synch and Windows. The fact that my CPU has not started cranking at a constant 50% CPU in 2 weeks is definitely a good sign.

Windows 7 Home Premium 64 bit, Service pack 1

iTunes 11.1.0.126

iPad 2 version 7.0.2 (11A501)

iPhone 4S version 7.0.2 (11A501)

Agree that after running iTunes 11.1.0.126 and devices with iOS 7.0.2 for periods of up to 4-5 days that the ATH.exe issue appears resolved.

However what I have observed in its place (or perhaps it was always there, being instead masked by the ATH.exe issue which always forced me shut down iTunes after 24 hours) is that connectivity of both my iPhone 5 and iPad 2 to iTunes over WiFi on the host Windows 64bit PC is erratic.

Both units connect occasionally to iTunes as evidenced by the 'Sync Now' button on the devices displaying as 'blue'[= Connected] but then after a variable period (minutes to hours) will revert to 'greyed out' [= Not Connected]. Typically the devices will 'seemingly' remain connected in iTunes, but as soon as an attempt is made to initate a Sync via iTunes the devices cannot be found and the device button(s) disappear in iTunes.

Sometimes I can force reconnection of the devices by restarting iTunes, or stopping / restarting WiFi on the devices, or restarting the Apple Mobile Device Service on the host PC. However there is no particular pattern to this behaviour that I can discern and there is no particular fix / intervention that always works.

These observations are supported by what seem to 100's of similar reports on the web dating back over the past several years, with users reporting a myriad of possible explanations and fixes for this issue which typically only work for a short period before the problem returns.

Frankly Apple seem incapable of making WiFi Sync work reliably on Windows based machines. My next devices will definitely not be Apple.

iPhone Model: 5

iPad Model: 2

iOS Version: 7.0.2

iTunes Version:11.1.0.126

WiFi Sync: Enabled

Windows Version: Windows 7 Ultimate 64bit Service Pack 1

Experience: ATH.exe issue appears resolved. WiFi recognition of devices in iTunes is erratic.

I may have something to add on the stability of WiFi iOS device connections to iTunes 11.1 on Windows 7 64bit machines and iPv6.

A couple of days ago, not long after my last post, I noticed iPv6 timeout errors for the Bonjour Service in the Windows Event Viewer after observing erratic connections of my iOS7 devices to iTunes 11.1 as I have described previously. In fact as *a lot* of users have described in Apple & other forums for most of the past serveral years.

I had switched off IPv6 on my Windows PC ethernet adaptor some months ago while attempting to troubleshoot the issue as a number of articles online attributed these type of errors to the Bonjour service 'choking' on iPv6, suggesting it was best to disable iPv6 at the Windows adaptor. In my case my Windows PC is connected by ethernet to the same router which serves WiFi to my iOS devices.

However this time I tried enabling iPv6 on the Windows PC adapter and voila! stable "Sync Now' connections for the past few days for *both* my IPhone5 (iOS7) and iPad2 (iOS7) to the same instance of iTunes 11.1 / same Windows 7 64bit PC.

What's more when I again switched-off iPv6 on the adaptor (ie. in order to test reproduceability of this observation) I saw an immediate return to the previous unstable behaviour with iTunes momentarility showing both iOS device connections, then dropping one connection when the second device was synced.

This suggests to me that the (presumably) updated Bonjour Service now being rolled out with iTunes 11.1 requires iPv6 connectivity to reliably support 2 or more iOS devices connected by WiFi to the same Windows machine.

iTunes appears to try using iPv4 connections when iPv6 is not available, but it seems iPv6 connectivity is required to maintain stable connections to multiple devices. This also seems to fit with some of the online technical documents I have read about Bonjour which suggests that iPv6 is used to maintain mulitple connections over a single interface.

Incidentally I don't dispute that turning-off iPv6 may have helped resolve connectivity issues for some users with previous versions of iTunes, particularly if they were only attempting to connect a single device, however I suspect iPv4 and iPv6 behavior has been altered in the lastest version of iTunes & so that it now requires iPv6 to be active on the Windows adaptor if 2 or more devices are connected.

I would be interested to hear if other users experiencing unstable 'Sync Now' connections between their Windows PC and their iOS devices can verify my experience.

So I just had the same problem. The process, ATH.exe was running over 30% of my CPU. However, I was able to fix the problem (on Windows 8) and this is what I did:

Go to control pannel and click uninstall a program. Right click on "Apple Mobile Device Support" and click "Repair."

Once I did that, the program disappeared from Task Manager and returned after maybe half an hour or less running at 0%.

@Biggie:

first of all, it would help if you would state the configuration with which you're making your observation, e.g.

iPhone/iPad Model:

iOS Version:

iTunes Version:

WiFi Sync: Enabled/Disabled

Windows Version:

Experience:

This helps tracking whether the problem has been solved with the latest release of iOS and iTunes.

Secondly, if you're running still on iOS 6.x, then what you think may have solved the problem may come back again in a day or two. This has been the almost unanimous experience of users in this forum. So, check back in 48 hours and report back if the issue is still solved after 2 or 3 days uptime.

I had the issue with Windows 7, later with Windows 8 and updated last Friday to 8.1. Still no WiFi sync, then I reinstalled iTunes completely described in http://support.apple.com/kb/HT1923 (do not forget to deinstall iCloud control panel). After that the sync is working on all my iOS devices, with iTunes 11.1.1 + 11.1.2. ATH.exe is normal since last Friday, 0 - 2% CPU.

iPhone 5: iOS 7.0.0

iPad 2: iOS 6.1.3

Windows 8.1 (x64) with the latest Windows updates (German edition)

WiFi Sync enabled on all iOS devices, sync is working

iPhone/iPad Model: iPhone 6

iOS Version:9.3.5

iTunes Version: 11.4 (18)

WiFi Sync: Disabled

MAC Version: 10.6.8 Mac Mini

Experience: broken for over a year, cannot load songs from iTunes to my iPhone, ath running rampant and cannot be killed. Apple has made my decade long utopia a ghetto by breaking stuff on purpose. Windows 10 seems like a better deal, and goodbye iPhone too