We have a fix for high CPU on MacOS when Microsoft Defender SmartScreen is enabled!


Thank you to everyone who shared and submitted feedback regarding Microsoft Edge’s high CPU usage when Microsoft Defender SmartScreen was enabled.  We investigated the issue to find there was a bug where Mac timer expiration notifications were continuously being queued. This caused Mac CPU to consistently sit at ~150%. Having diagnosed the issue, we have created a fix which is now in both Microsoft Edge 79 and 80 for Canary, Dev and Beta. Please update your version of Microsoft Edge to the latest version to receive the fix. If you continue to experience performance regressions, please submit feedback through Edge, specifying how the issue can be reproduced and/or submit a trace with the feedback.

Thanks so much for helping us improve Microsoft Edge!

2 Replies

@Elliot Kirk Let's hope Apple can similarly fix their high CPU issues in Safari 13 for MacOS and iPadOS, currently breaking our SharePoint Online intranet. Edge is my new go-to on MacOS, but alas everything is Webkit on iPad. 

6/17/21 Still a huge problem occuring on latest software Big Sur (11.4, edge 91.0.864.48) on 2015 Macbook Pro. CPU @ 100%+ and laptop 20C warmer when edge is running single tab open doing nothing. Turning off Defender SmartScreen instantly drops CPU usage instantly.

Another Late 2013 MBP running Catalina with Defender SmartScreen shows no CPU consumption problems.