5 ms·
It would be great to see performance deltas for AMD CPUs too, especially since Meltdown only effects Intel and AMD patches for Spectre Variant 2 are considered
by voidlogic 9y ago
It would be great to see performance deltas for AMD CPUs too, especially since Meltdown only effects Intel and AMD patches for Spectre Variant 2 are considered optional. I would also be nice to see a discussion of AMD's ASID and any differences it has with Intel's PCID when when PCID is addressed.
- mangix 9y agoWhat's being tested here has nothing to do with Spectre. Only KPTI.
- bitL 9y agoMaybe a better formulated question would be - do the Meltdown changes to kernel impose performance penalty on AMD processors as well (regardless of exploitability)?
- paulmd 9y agoThey are not enabled for AMD by default. If you force them to be enabled, they impact performance (of course).
- jnordwick 9y agoEven on Intel there should be an evaluation of performance cost vs risk. If you are not running unknown code, you may not want to enable kpti either.
- paulmd 9y agoExtremely correct. Database and frontend servers are hit pretty hard, nothing in the middle is hit. But neither of those ends is actually running untrusted code, for the most part. I predict a decline of the "hyperconvergence" server and a return of the usual "database server" + "app server" + "frontend server" combo.
- voidlogic 9y agoThanks, I understand now. What I didn't realize is that KPTI is only related to Meltdown mitigation. Thanks.