[runjake]

What does it matter, in this context?

If it's about bare metal vs. virtual machines, know that Spectre affects virtual machines, too.

[rkagerer]

I think they are implying disabling them (if on) could squeeze you out a bit more performance.

[runjake]

Ah, I did not think of that angle, which is substantial. Thanks.

[egorfine]

Substantial as in "up to 30% of performance".