I've found a fix
Add:
options snd-intel-dspcfg dsp_driver=2
To /etc/modprobe.d/alsa-base.conf and reboot
At first audio was playing at the incorrect rate (low pitched) which I
think is an ACPI issue. Going into the bios and saving then exiting and
letting Ubuntu boot up and audio is returned to
The problem seems to be that the cpu will not run in a higher power
limit for any length of time
** Attachment added: "s-tui video of full load behaviour"
https://bugs.launchpad.net/ubuntu/+source/thermald/+bug/1958328/+attachment/5564123/+files/Screencast%20from%2028-02-22%2009%3A56%3A33.webm
Also affects my Archos Cesium 90 with the same basic specification
I found booting back to the 5.11 kernel in grub after the 5.13 kernel
upgrade while returning audio had pitch shifted the audio very low and
caused slow video playback
The only current solution I have is to install the generic 5.4
