bug#74855: 30.0.92; dired - slow copy across (wireless) LAN

[Stefan Kangas]

Christopher Howard <christopher@librehacker.com> writes:

> Hello. Recently I was using dired to transfer 600 files, with about 2GB data 
> total, across our LAN (one wi-fi hop involved). The source was a local 
> directory, and the target was an SSH host on the LAN. I marked the files I 
> wanted with dired-mark-files-regexp, and then used dired-do-copy to send them 
> to "/ssh:<snip>@<snip>:/home/<snip>/<snip>". This took a really long time. 
> Actually, the copy was still going after about 15 hours (overnight) though I 
> could see it had not frozen up, but was still moving files.
>
> Using scp directly, from Gnome console, I am seeing transfer rates of about 
> 2.5 MB/s over the same path. So, I'm wondering why the large disparity. Could 
> somebody explain further how Emacs goes about moving the file data and where 
> the bottleneck would be. Is there room for improvement in this functionality?

Michael, any comments?