3 ms·

But poor single-threaded performance doesn't imply that the core is sitting idle. It may well be running as fast as it possibly can and using all the shared com

But poor single-threaded performance doesn't imply that the core is sitting idle. It may well be running as fast as it possibly can and using all the shared components of SMT leaving nothing for the other thread to use. In the same way the single-core performance may be really good yet everything shared by SMT is still only utilized to half its potential so the 2nd thread runs almost as fast as the first.

FeepingCreature 6y ago
Yes. I think the point of the article was more that people don't understand where HT/virtual SMT gets its speedup from.
- magicalhippo 6y ago
  From the very start I've always heard HT being good for memory-bound applications. That's how it was explained and marketed. Some years ago I worked on such an application, and we got a ~80% speed increase going from 4 threads to 8 threads on a 4-core with HT enabled. I wouldn't expect compute-bound applications to get anywhere near such gains. Makes me wonder where those with a misconception got it from.