Comment 40 for bug 1759920

For me, on my laptop (Intel(R) Core(TM) i5-4330M CPU @ 2.80GHz) with Kubuntu 17.10, the 4.13.0-38-generic kernel (signed image) has the same problem.
In fact it was slightly worse, a it seems to have wiped out my Ubuntu UEFI booting (boots straight to Windows - I can get to the Ubuntu menu from there and that works).
Now fixing that...

Reverting to the older intel-microcode with 4.13.0-38-generic is OK.