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

Great News!! (Maybe)

Just updated my iTunes to 11.01.12 with WiFi Synch "On".

My Windows CPU is running at 5% while idle with iTunes open.While the Synch is Synching, CPU is running at 16% low & 30% high and only 2,800 memory!

Seems like it's running like a charm!

Could Apple really be on the ball and fixed this finally?

Please check your systems after you update iTunes and post your results!

Don't get your hopes up, the problem is still there.

Great News? Quite Unlikely. As most posters to this thread have observed the problem is always temporarily suspended after a system restart, becoming evident again usually within 12-72 hours.

The only observations that are therefore meaningful are those made at least 72 hours after an iTunes upgrade / restart.

Since the iTunes 11.0.1 update has only been available for less than 24 hours, your optimism, while understandable iTunesPro is misplaced.

You are correct!

I updated iTunes and restarted and thought it was fixed.Back to 50% plus CPU usage.

My bad. I'll be a little more patient next time.

Can't believe Apple has not fixed this problem.

:-(

I've been dealing with this for a year.  Apple clearly doesn't care. 

https://www.facebook.com/GetAppleITunesFixed

#itunesSucks

I have filed a bug report #12898549 on https://developer.apple.com/bugreporter/

I created mini-dump files for the spinning processes and included stack traces.  Hopefully the technical details help them.   We'll see what happens.

I've been having ATH.exe crashes for the longest time. I'd like to say since 10.5 but that's just from memory.

And yes, am running Win 7 Pro x64 along with everyone else.

I had an interesting development. Not sure if its "coincidental" but worth mentioning.

As expected, ATH.exe quit on me pretty soon after I booted the PC.

Left it for a few hours and noticed that when I plugged the iPhone 5 (iOS 6.0.1) in (even though its on Wi-fi sync), it wasn't registering in iTunes.

Curious, I found ATH.exe in C:\Program Files (x86)\Common Files\Apple\Mobile Device Support and tried running it without and with Admin rights. No luck on seeing the iPhone using USB.

However, did note that Apple Mobile Device service is running. And from discussions so far, realised that it was tied to ATH.exe.

So, got into Services with Admin rights (Ctrl-Shift-Esc for Task Manager > Click Services tab > Click Services button with UAC shield), disconnected the iPhone and restarted the abovementioned service (Right Click > Restart).

Started up iTunes and connected the iPhone. It works! iTunes (11.0.1.12) sees both my 3GS and 5 via Wi-fi sync.

Until this issue is fixed, net stop and start commands might be necessary.

I use this batch file to do the job (echo comments optional):

@echo off

Echo As a precaution, disconnect any USB iOS devices and close iTunes.

pause

net stop "Apple Mobile Device"

net start "Apple Mobile Device"

echo iTunes should recognize your iOS devices now.

echo Open iTunes and connect via USB to check connectivity.

pause

Because there is no restart command for the net command, stopping and starting is the only way to effectively restart the service. I'm also hoping this issue might fix the cpu problems but doubt it.

The essential commands in an elevated command prompt are in bold.

If you make the batch file, be sure to Run as Administrator otherwise the service won't stop and start.

Hope this helps someone. Good luck.

Following up on this issue, I found that AppleMobileDevicesService process was pinging at 25% constantly when the PC was idle.

Closing iTunes didn't stop the process however, restarting the abovermentioned service stopped the process from using 25% of the cpu. It also stopped the offending process.

Hope this info also helps.

Yes, that is consistent with the behavior I see.   To summarize:

1) From a cold reboot, if you start iTunes and do a Wifi sync, it's likely to work.  Things will be fine for a while.

2) If you leave iTunes open for several hours, affected users will find ATH.EXE and/or AppleMobileDeviceService.exe hung, consuming a full CPU core.  On a dual core you'd see 50% usage, quad core, 25%.

3) Once either of these hangs, wifi syncing will no longer function. 

4) You can kill these services (killing ATH.EXE and/or restarting the Mobile Device Service) and things will temporarily work again.

This means that the best workarounds are:

1) Not using wifi sync

2) Close iTunes after syncing.

3) Set up scripts that periodically kill ATH.EXE and kill/restart MobileDeviceService.  

4) Stop usng Apple products. 

iOS 6.0.2 just arrived on my iPhone 5 with a claim to fix bugs that "... might affect wifi."

We'll see.

I am the same issue too.  Windows 7 32 bit with very latest iTunes 11.  Disabling wifi synch is a work around.

We don't want work arounds, we want in working correctly, as advertised, and no bugs making iTunes an almost intolerable listening experience.

Don't get your hopes up.   Apple software development has a quality process problem, obviously.  In the mean time they'll continue to be focused on new features while leaving bugs to linger indefinitely.

Tim Cook doesn't appear to be a leader to me - unless you consider the blind leading the blind as leading.

Did anyone get any response when the opened a ticket?

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