High CPU usage on macOS

Brass Contributor

For some reason, I get very high CPU usage on Edge Dev v79.0.294.1 on macOS 10.14.6


Attached is a screenshot of the Browser Task Manager with Edge at 180% CPU usage (somehow?)

My laptop's fans are running with only Edge opened and a couple of tabs which aren't very resource intensive. (The same CPU usage shows up on Activity Monitor).


Screen Shot 2019-10-10 at 10.49.27 AM.png


Edit: This doesn't seem to happen all of the time. Perhaps a specific number of tabs? Or a specific website is causing this. I still find it strange considering none of the tabs I have opened are resource intensive. 
Also, I'm not getting this issue on Safari (I haven't tried on Chrome). 

31 Replies

@pandawan I'm seeing the same thing here on masOS Catalina. I didn't capture the in-browser process reader but on the system level Edge's CPU usage increased exponentially with time. The strange thing is I'm looking at static pages, downloading files from one of the open pages, but nothing that I can think would need the CPU.




please try disabling Microsoft Defender SmartScreen from the settings.


and see if it fixes the issue.

That seems to have worked. (I'll reply here if I get this issue again).

Thanks :)

@pandawan I'm seeing this as well. MacOS Mojave.

which Edge insider channel?

@HotCakeX Edge Dev



For me, Edge Dev has been excellent from a memory / cpu perspective on MacOS up until I upgraded to Catalina.  Since then, I've encountered the same issue you describe.


However, following the suggestion in this thread, I have disabled Defender SmartScreen, and that seems to have resolved the issue for now. Hopefully the Edge dev team can resolve the issue to enable MacOS users to turn the feature back on again later. 


On the other hand, MacOS Catalina doesn't seem very stable as a whole. It is very laggy. I wish I hadn't upgraded!

@timbowesI don't know much about Catalina, but it seems that you could remove it from what I've seen on the web.

@cjc2112 I think that only applies to the Beta, unfortunately. Catalina was the latests MacOS upgrade, released on 7 October, 2019. Potentially I could revert to a back up though. :)

I'm experiencing the same problem on Windows 10

the problem is no longer isolated to MacOS only..

@HotCakeX Thanks for this. Your fix worked for me on MacOS Mojave 10.14.6. I've been experiencing high CPU with Edge 80.0.328.4 (Dev channel) and for at least two weeks/builds before that. Thanks!

You're welcome :)
"" We have a fix for high CPU on MacOS when Microsoft Defender SmartScreen is enabled! ""


I'm still getting very high CPU (300%) usage at random intervals on macOS. I have kept Windows Defender Smartscreen completely disabled and this issue still occurs. (On Edge Dev v81.0.416.6, macOS 10.15.3)


Are there any plans to fix or any way for me to send some kind of diagnostic info to hopefully help get this issue fixed?

Yes, I have the same problem. Tried stable(80.0.361.56) and beta(80.0.361.53) versions with Smartscreen disabled. It occupies 95~150% cpu after some random time and can not be closed properly.

It might be worth noting the website you were trying to access at the time, as this can also have an impact on CPU / RAM consumption. 


For example, we currently have a very similar experience in Safari 13, when accessing SharePoint Online pages using a particular web part. The issue (we believe) is partly due to changes in Safari 13, which have caused incompatibility with elements of this web part. In short, the two elements --- browser and website --- have to be considered.


One further note: I have been experiencing massive CPU spikes in other applications in MacOS Catalina recently e.g. Affinity Photo & Affinity Publisher. These previously ran seamlessly, so I am starting to wonder whether OS update 10.15.3 is itself the issue. We should really call it MacOS Vista! :)

Thank you. However my situation is that the Edge consumes very high cpu even after I closed all tabs. And if this happens, I can't terminate it without "Force Quit". So I guess this does not relate to any particular website.

It might be a compatible issue with Catalina. Personally, I really like some security improvements with Catalina, think they are heading to the right direction. Such as its "read-only file system", it might be a decent solution to the system security and upgrade stability in a long run. But such many problems are indeed frustrating. So yes, I can agree on the term MacOS Vista :)

@yuguo Yeah, when the CPU starts to spike, closing all tabs does not fix the issue and I also am forced to "Force Quit" it. 


It's possible that some specific pages are causing some internal parts of edge to crash continuously. That would explain why closing all tabs does not stop the crash, once the crash loop starts it doesn't stop. (I'm just speculating at this point).