High CPU and energy usage in Safari Energy impact of Safari is extremely high on my Macbook Air Mid 2013 El Captian 10.11.2. It lead to high usage of CPU (Temperature ~65.0°C) and the CPU fan is running in full speed (6500.0 RPM) constantly.

I have tried so far:


Clear all Safari cached
Restart laptop
Remove/disable all extensions
Uninstall all the software that might possibly affecting e.g. Anti-Virus


The issue is only happening in Safari. Chrome and Firefox are both OK.

Thanks for helping in advance!

CPU:


Energy Impact 1:


Energy Impact 2:


CPU Temperature and Fan Speed:


Network Activity:
I know this is probably a little late but I hope it helps someone else. 

I found the reason Safari was using so much CPU was due to faulty permissions. It was stuck in a loop trying to access a file it couldn't. 

To see if this might be an issue for you run:

sudo /usr/libexec/repair_packages --verify --standard-pkgs /


And see if there are any files wile damaged permissions.
For me it was:

Permissions differ on "Library/Java", should be drwxr-xr-x , they are drwxrwxr-x .
User differs on "private/var/db/displaypolicyd", should be 0, user is 244.
Group differs on "private/var/db/displaypolicyd", should be 0, group is 244.


So it is a good chance Java permissions are the culprit. To fix run:

sudo /usr/libexec/repair_packages --repair --standard-pkgs --volume /


And then restart Safari. For me this immediately dropped CPU use from 150% to 14%. 

One should note if you have 100s of faulty permissions, it could be an early sign of disk failure. As always, keep backups.

I hope this helps someone else out there.