Technology changes quickly, threads are being closed, ... this bug have been with us for years, about half a decade!
https://bugs.launchpad.net/ubuntu/+s...er/+bug/882566
This regression (CPU hang bug) happened somewhere between Ubuntu 8.04.4 and 10.04 (introduced also in Kubuntu, at least 14.10).

Workarounds to make these laptops usable:
1) disable AHCI in BIOS (to prevent hang during booting)
2) buy an external USB sound card.

Any hope for a fix?

Realtek ALC268 SerP3 SerP4 Compal IF90 JFL92