A 5x reduction in RAM usage with Zoekt memory optimizations

Re:A 5x reduction in RAM usage with Zoekt memory optimizations by cbm-vic-20 on Thursday August 19, 2021 @04:03PM (#28238648)

Not directly related to the linked content, but "N times less" never really made that much sense to me. In this case, I'm guessing "5x reduction" means "80% less"? Or "20% of the previous usage"?

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Re:A 5x reduction in RAM usage with Zoekt memory optimizations by DistractionRect on Thursday August 19, 2021 @04:46PM (#28239172)

N times less usually just means it uses 1/N. So this would mean it uses only 20% of the memory it used originally.

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Re:A 5x reduction in RAM usage with Zoekt memory optimizations by rusk on Thursday August 19, 2021 @06:18PM (#28240061)

Yeah it doesn’t make sense as the x in 5x I would have thought repetesents a multiplication rather than (divide)

It would make more sense for me to say a fifth, or 1/5

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Re:A 5x reduction in RAM usage with Zoekt memory optimizations by MichaelBurge on Thursday August 19, 2021 @07:44PM (#28240713)

    log(5x)  =  log(5) + log(x)
    log(x/5) = -log(5) + log(x)

So the difference is just a sign change on a log scale. And it's natural to use a log scale when working with percentage changes.

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Re:A 5x reduction in RAM usage with Zoekt memory optimizations by rusk on Friday August 20, 2021 @04:19AM (#28243853)

Natural for who?

Perhaps better expressed as “5 fold”.

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Re:A 5x reduction in RAM usage with Zoekt memory optimizations by tyingq on Thursday August 19, 2021 @04:10PM (#28238723)

"We went from 1400KB of RAM per repo to 310KB with no measurable latency changes."

So, not exactly, but close. ~22% of previous usage.

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Re:A 5x reduction in RAM usage with Zoekt memory optimizations by nijaru on Thursday August 19, 2021 @04:15PM (#28238794)

Yes that is correct. It's not always the most intuitive language.

5 times less than 20 would be 4 or (20 * 1/5), the same as 20 is 5 times more than 4.

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Re:A 5x reduction in RAM usage with Zoekt memory optimizations by ksec on Thursday August 19, 2021 @04:30PM (#28238974)

Yes it is the marketing speak of 80% less. And generally speaking works much better than percentage.

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Re:A 5x reduction in RAM usage with Zoekt memory optimizations by nytgop77 on Thursday August 19, 2021 @05:49PM (#28239792)

I saw advertisements "now 20% cheaper!", while price change (original->new) was 30€->25€.

Marketing always finds a way.. 5/30=16.6%, 5/25=20%

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