rate limit definition

[ghost]

I have problem about slow download speed. my internet connection is able to download 3 megabyte persecond.
I run below command but it downloads with 107.86Kb. What is problem, my definition or not ?

youtube-dl -o "%(autonumber)-%(stitle)" -r 3M

[phihag]

-r can only lower the download speed. It may be just youtube throttling the download. If leave -r 3M out, does the speed improve?

[ghost]

-r, --rate-limit LIMIT download rate limit (e.g. 50k or 44.6m)

It is clear that this parameter does not lower the download speed. It just defines the target download speed.
Actually, I have doubt about the definition of 3 megabyte. Is 3M really refer to 3 megabyte or not ?

I have made some experiments in order to clarify the usage & effect of "-r" parameter.
youtube-dl -t http://www.youtube.com/watch?v=hYgJAN1Ol5g
youtube-dl -t -r 3M http://www.youtube.com/watch?v=hYgJAN1Ol5g

Result is astonished me. Second one's download speed reached to 1.5M then fell to 70.kb.
First one was downloaded with 50k. This shows script and -r works successfully but youtube limits speed.

I am sure, bacause I have downloaded one music file with 2.5Mb per second with this script ( -r 3M )

[phihag]

We're always dealing with bytes and not bits, so 3M is three MegaByte.

I'm afraid that you have misread the documentation - we can not magically make youtube download faster. By default, youtube will push through the first seconds with great speed, and then fall back. However, the algorithm isn't always applied, and ISPs love to monkey around with those data transfers (and install their own caches).

[ghost]

I am sorry, I dont know "how I made that mistake".
You are right, thank you for your interest and immediate answers :)