
What We Talk About When We Talk About Performance - ingve
https://randomascii.wordpress.com/2018/02/04/what-we-talk-about-when-we-talk-about-performance/
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lostmsu
Basically, the whole article is that cutting time of X by 90% makes X 10 times
faster, not "90% faster".

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MaxBarraclough
See also 'Why We Should Measure by Gallons per Mile, Not Miles per Gallon':
[https://www.popularmechanics.com/cars/a12367/4324986/](https://www.popularmechanics.com/cars/a12367/4324986/)

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lostmsu
Seems to be a stupid article. Both ways to compare are very wrong either way.
The correct way is to divide, and then mpg vs pgm does not matter. It just
happens, that subtracting in pgm is perceived closer to the real rate you get
by division.

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nkurz
Let's go a level deeper: why do people so often write "90% faster" to describe
something that is "10 times as fast". If they were using "90% faster" to
describe something that was "1.9 times faster", the likely explanation is that
they are trying to deceive their audience while remaining technically correct.
But why would someone bragging about a genuine improvement choose a wording
that undercuts their message?

My guess would be that some authors feel that "10 times faster" is low brow,
unscientific, and therefore unconvincing, while using a percentage comes
across as more precise, authoritative, and thus convincing. As others copy
this, the social effect strengthens. Are they possibly right about this? Is
claiming "90% faster" perhaps more effective marketing despite being wrong?

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paulddraper
> My bold claim

> If you optimize a task so that it takes 90% less time than before then that
> is a ten-times speedup, and it should be described as such.

Hopefully not too bold :)

If I said revenue doubled (increased 100%), I assume that means I get 2x the
money over the same period of time.

If I said performance doubled (increased 100%), I assume that means I get 2x
the throughout, tasks, start ups whatever over the same period of time.

Just makes sense.

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AstralStorm
This is why in realtime applications the correct measures are x times faster
than realtime (relative throughput) or total runtime (absolute throughput) and
a full histogram of response times. (absolute latency)

Relative latency would be used in games perhaps. (x times faster response than
frame time)

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zwieback
The article is way too wordy but I appreciate the Raymond Carver reference

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oddeyed
Relevant xkcd: Percentage Points.

[https://www.xkcd.com/985/](https://www.xkcd.com/985/)

