Obscene CPU usage with Safari (Version 14.0 (15610.1.20.4, 15610) on Catalina

I was invited to the AppleSeed beta yesterday and have installed Safari Version 14.0 (15610.1.20.4, 15610) on Catalina (10.15.6) - unfortunately it seems to love CPU usage.

With only Safari open, with no websites and all extensions disabled, it consistently uses 100% of the CPU on my MacBook Pro. As you start to actually use Safari, this usage climbs.

With just two websites open (https://developer.apple.com/download/ and this page https://developer.apple.com/forums/create/question), Activity Monitor reports that Safari is using 1,196% CPU and the fans are going full speed.

Is anyone else using the Safari beta on Catalina experiencing the same?

I've just reported this via Feedback Assistant.
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BeauGiles
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I have the same issue and also reported it yesterday. I hope, that there will be update soon because I did not find any info how to revert Safari to stable version, currently it is unusable.
Posted by
beny
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Same here, basically unusable!

Posted by
perlguy67
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Same problem after update macOS to 10.15.6 with default safari 13.1.2
Posted by
AleksandrIt
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Same version here, at some point and without a lot of open tabs, it even passed the 500% cpu usage, which is insane.
Posted by
Netanel_S
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Safari v14.0 (15610.1.23, 15610) - Problem fixed.👍
Posted by
Netanel_S
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Same experience. And you can't downgrade to the released version.
Use Safari Technology Preview to avoid the problem.
https://developer.apple.com/safari/technology-preview/
Posted by
jwestveer
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I've had this problem for a while and was using Safari Technology Preview without issue but still tried to fix regular Safari. I think I figured it out: Try looking in ~/Library/Containers/Safari/Data/Library/Caches. Clearing out my caches seemed to have fixed MY problem. I suspect cryptomining (cryptojacking) malware disguised as cache files.

Hope this helps "someone" out there.

Posted by
davein310
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