Performance "speed limits"

By: Travis Downs (, June 11, 2019 7:12 pm
Room: Moderated Discussions
anon ( on June 11, 2019 7:06 pm wrote:
> Travis Downs ( on June 11, 2019 1:23 am wrote:
> > I wrote something about performance speed limits, which is basically a list of things
> > that might limit your code (mostly loops) to a specific level of performance. It's
> > quantitative, in that it tells you exactly how many iterations/cycle you'll get if
> > you hit a particular limit. I've used it in practice and find it effective.
> >
> > Have a read if it interests you. Feedback is welcome - I don't have a comments
> > system set up* but you could reply here or open an issue on github.
> >
> >

> >
> > * BTW, if anyone knows of a comments that works with static sites, and which is not
> > Disqus, has no ads, is free and fast, let's me own or export the comments, and doesn't
> > require me to be a wizard in any particular webtech, I would like to hear about it.

> "There are only 5 fused-uops12 here, so maybe this executes in 1.25 cycles? Not so fast - it
> takes 4 cycles because there are 4 loads and we have a speed limit of 2 loads per cycle13."
> 2 cycles?

Thanks, the test correctly shows 2.01 cycles but the text was wrong.

Fixed and credited.

< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
Performance "speed limits"Travis Downs2019/06/11 01:23 AM
  Performance "speed limits"Adrian2019/06/11 03:52 AM
    Performance "speed limits"Travis Downs2019/06/11 09:28 AM
  Performance "speed limits"Paul A. Clayton2019/06/11 05:04 AM
    correction of my corrections!Paul A. Clayton2019/06/11 05:07 AM
    Performance "speed limits"Peter E. Fry2019/06/11 07:19 AM
      Performance "speed limits"Travis Downs2019/06/11 09:36 AM
    Performance "speed limits"Travis Downs2019/06/11 09:26 AM
  Performance "speed limits"Branches2019/06/11 08:04 AM
  Performance "speed limits"anon2019/06/11 07:06 PM
    Performance "speed limits"Travis Downs2019/06/11 07:12 PM
      Thank you, very nice writeup (NT)anon2019/06/11 07:37 PM
  Performance "speed limits"anon2019/06/11 07:34 PM
    Performance "speed limits"Maynard Handley2019/06/12 10:13 PM
    Performance "speed limits"Travis Downs2019/06/13 01:05 PM
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