Re: Curl's network performance is slower than IDM.

On Fri, 19 Jun 2020, Hongyi Zhao wrote:

> Another consideration came to my mind the speed computation method used in
> two tools. In detail:
>
> speed = downloaded_bytes / time_duration

Showing download speed is somewhat more complicated than so. For example,
imagine a download that goes like this:

First 60 seconds at 100% speed
Then 60 seconds at 5% speed
Finally, it recovers and goes back to 100% speed.

What "transfer speed" do you show in the various phases? In curl's case, we
show two speeds: we should the full "downloaded_bytes / time_duration" average
one ("Average Dload") and then we show the "Current Speed", which is the
average speed over the last 5 seconds. That makes it show 100% "Current Speed"
at the end but the "Average Dload" will never get up to 100% again after the
first phase.

Other tools will do it differently and some people will have strong opinions
on what's wrong and what's right and what data to include and not within the
"downloaded bytes".

> What I want to confirm is whether the different criterions for data
> package statistics are used for speed computation between IDM curl.

Given what Patrick explained, I would say that's pretty much concluded now:
they're done differently.

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