Ask the great god about loading and unloading problems

Download and download of PHP.
My LAN upload a 100M file, and then move to a path below, the total time is almost 12 seconds (PC machine Server), that is, can reach 8M per second, the time is basically spent on the network transmission above; But the same file I download (single-threaded), can only reach 3M per second, Even if the use of such a file to download thunder, you can reach 5M, the great God can tell, how is this caused?
or introduce the difference between PHP upload and download.
Thank you

Reply to discussion (solution)

So how do you download it? Through a PHP program?

is downloaded via Php,ie. If you download through thunder, the speed is not too much.
And I'm the one who's walking. HTTPS

Upload, data stream sent without PHP intervention, PHP just finished moving the file action, so soon
When downloading, you use PHP to read the file and block out, due to the intervention of PHP, so it slowed down
Browser is not a professional download tool, naturally slower than thunder

In addition, the upload may be multi-channel transmission, and the download must be a single lane. So the speed must be different.

Thanks for Xuzuning's explanation.
But I still think it's incredible.
For example, the location of the download, I do not read the file through PHP, directly put the file in the browser or thunder access to the place, the speed is still very slow.

This is what I said "another", only the professional server to support multi-Channel download (breakpoint continuation). Of course, PHP code can also achieve 206 response

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