[smcl]

That's actually a nice way to look at it, and helped me see why and in what cases I dislike this phraseology - I couldn't really articulate this before. So I think my issue is presenting something in time-units per action and talking about an optimisation of it as multiples of actions per time-unit faster.

I hate it a little less now :)

[mort96]

Well, speed is distance/time. For the "speed" analogy to make sense when talking about performance, we have to translate "distance" to something more abstract, let's call it "work". That means we have speed = work/time. If you have 1 unit of work (say you think of "build the whole app" as one atomic operation) which used to take 20 seconds, and now it takes 2 seconds, you went from a speed of 1/20=0.05 to a speed of 1/2=0.5, which is a 10x increase.

Hence, "it's 10x faster" is a valid way to write "it does the same work in 1/10 the time".

[smcl]

Yeah I get it - it just feels a bit clumsy to use the flipped units when summarising the optimisation. Just a personal taste thing though.

I still think "X times less than" can GTFO though - as in 10,000 is "seven times less than" 70,000 - which is the kind of thing I'm seeing more recently. That wasn't mentioned in the article though, it was maybe a bit unfair to lump them together.