Comment 9 for bug 1333294

I originally reported this issue in https://bugs.launchpad.net/ubuntu/+source/linux-hwe/+bug/1698118.
Just now I found this bug report so I'm marking mine as duplicate.

In the meantime, I had reported it upstream in the kernel in:
https://bugzilla.kernel.org/show_bug.cgi?id=196157

Thanks to the author of http://flaterco.com/kb/PAE_slowdown.html for the very nice overview of the issue and of the possible workarounds.