Re: accleration of file transfers

[Michael Albinus]

address@hidden (Haines Brown) writes:

> When files are being uploaded to a server, there is a regular time
> spacing between each file, perhaps 2 or 3 seconds. However, if I move
> my mouse over the emacs window, the speed suddenly about doubles, and
> with the time of file upload being a function of the file size. 

Tramp needs to receive data from running processes, which is done by a
loop over `accept-process-output'. A loop, because usually data are
received in chunks. This function has a time out in case no output did
arrive. Unfortunately, Tramp is conservative in calling this function
- it doesn't detect soon enough that all data are received, and
therefore this function is called more than really necessary.

Moving the mouse is an input event which also allows also receiving
output. Therefore, Tramp is faster because it gets its data faster.

> Is there any configuration that might reliably give the faster upload 
> rate? 

What you can try to do is an out-of-the-band method like scp instead
of ssh, which does not transfer the data via Emacs buffers but
directly.

And of course, you could try Tramp 2.1.4. It contains already several
performance improvements, which might help you. But likely moving the
mouse would accelerate it as well :-)

Best regards, Michael.