Hardware & Technical Intel Skylake and Kaby Lake CPU's have nasty microcode bug.

[shadragon]

During April and May, Intel started updating processor documentation with a new errata note, and over the weekend we learned why: Skylake and Kaby Lake silicon has a microcode bug.

The erratum is described in detail on the Debian mailing list, and affects Skylake and Kaby Lake Intel Core processors (in desktop, high-end desktop, embedded and mobile platforms), Xeon v5 and v6 server processors, and some Pentium models.

The Debian advisory says affected users need to disable hyper-threading “immediately” in their BIOS or UEFI settings, because the processors can “dangerously misbehave when hyper-threading is enabled.”

Full article here:

https://www.theregister.co.uk/2017/06/25/intel_skylake_kaby_lake_microcode_bug/

 

[Porina]

That's over-stating it a bit. Skylake has been out for almost two years now, so think of the many i3 and i7 CPUs sold since. This bug requires a highly specific condition and if you haven't encountered it already, are you likely to? It'll be blamed for anything going wrong by ignorant users, just like the previous AVX bug, regardless of the true cause. The number of people actually impacted by this will be tiny, and I'd suggest only in those cases is it worth disabling HT. Keep an eye open for bios or other microcode updates but no need to panic.

 

[Patrick_68000]

I believe that the Pentium also had a memorable bug