The Activity Monitor shows "AMPDevicesAgent (Not Responding)" and its using 99.9% CPU.

Question

Level 1

79 points

The Activity Monitor shows "AMPDevicesAgent (Not Responding)" and its using 99.9% CPU.

iMac Late 2012. OS 10.15.7. SSDs installed in place of original HD about 4 years ago. iMac working really really well after SSDs installed. Recently (maybe two weeks) many/most operations are quite slow and the dreaded beachball has made an unwelcome return into my life. Something is wrong.

Etrecheck says my iMac may "be considered obsolete". (I know. Upgrading soon - meanwhile......).

But Etrecheck also says my iMac performance is "Excellent".

One clue - when I attach my iPhone to the iMac for syncing and backup, I notice in the Finder Window, on the left-side where the Menus are, that the entry/icon/progress circle for the iPhone gets stuck at about the 75% mark. I note that the AMPDevicesAgent is somehow involved in different Apple devices talking/connecting/syncing to/with each other. So, there's a possible clue.

I opened Activity Monitor which shows ""AMPDevicesAgent (Not Responding)" and, its using "99.9% CPU"

Can anyone assist? I know how to use an iMac for the basics. I am NOT a techie or proficient in any aspect of IT. If you are able to assist could I ask you to explain/suggest things to me as if I'm 12 years old.

Thank you, in advance of any assistance

iMac 21.5″

Posted on Feb 28, 2025 8:54 PM

Reply

Answer 1

Top-ranking reply

rkaufmann87

Level 10

148,522 points

Mar 3, 2025 9:30 PM in response to Figgy

As mentioned your compute has not been restarted in 72 days, to be 100% honest that is not okay. Mac OS should be restarted about 1x per week, not every few months. It has to do maintenance on itself and it cannot do that unless you restart the computer. To be really blunt, I suspect that is the main cause of your problem.

Reply

Answer 2

den.thed

Level 10

92,326 points

Mar 3, 2025 9:13 PM in response to Figgy

The 2012 iMac hasn't been restarted in 72 days.

I've gone as long as 90+ days between restarts.

But the difference was, that my Mac had more RAM and little if any Swap Used.

Other than being Obsolete and unable to run anything later than macOS 10.15 Catalina.

Your 2012 iMac seems to be in good working order.

--------

You are spot on.

AMP Device Agent is the service that syncs your iOS devices with your Mac.

What I would do is Restart the iMac and then re-connect the iPhone to see if that helps.

If not, then I suspect that there is a compatibility issue between the old macOS and the iOS versions.

For some references articles:

If your Mac says that a software update is required to connect to iPhone or iPad - Apple Support

Use the Finder to sync your iPhone, iPad, or iPod touch with your Mac - Apple Support

Sync your iPhone, iPad, or iPod using your computer - Apple Support

Reply

Answer 3

Figgy Author

Level 1

79 points

Mar 3, 2025 10:13 PM in response to rkaufmann87

Thanks rkaufmann87,

As you can see, den.thed, thought similarly. I did a restart and I think that's done the trick. The Activity Monitor shows that the AMPDevicesAgent is no longer "Not Responding" and the iPhone, which I've just attached, is syncing and, now, backing up quite nicely.

A simple restart would never have occurred to me. A weekly task from now on.

Thanks so much to both of you. This discussions forum is just terrific.

Figgy.

Reply

Answer 4

Figgy Author

Level 1

79 points

Mar 3, 2025 10:07 PM in response to den.thed

Thanks den.thed,

As you can see, rkaufmann87, thought similarly. I did a restart and I think that's done the trick. The Activity Monitor shows that the AMPDevicesAgent is no longer "Not Responding" and the iPhone, which I've just attached, is syncing and, now, backing up quite nicely.

A simple restart would never have occurred to me. A weekly task from now on.

Thanks so much to both of you. This discussions forum is just terrific.

Figgy.

Reply