Re: Why is Emacs so slow when used remotely?

[Tim X <timx@nospam.dev.null>]

"Russ P." <russ.paielli@gmail.com> writes:

> On Sep 20, 6:40 pm, des...@verizon.net wrote:
>> "Russ P." <russ.paie...@gmail.com> writes:
>> > As I explained a few days ago, I am trying to switch from XEmacs to
>> > Emacs so I can use Ensime (an Emacs-based IDE for Scala). I finally
>> > got my .emacs file debugged, but now I am finding that Emacs seems to
>> > be very slow when used remotely.
>>
>> > When I work from home, I login from one Linux machine to another using
>> > ssh -X over a high-speed Internet connection, using my home machine as
>> > an X terminal for my work machine. I am using Emacs 23.2.1 on Red Hat.
>> > I am finding that opening a file or switching buffers by middle-
>> > clicking in dired or the buffer menu takes approximately 20-30
>> > seconds. With XEmacs it takes less than one second. I hope I am doing
>> > something wrong that can be corrected, because I'll grow old sitting
>> > around that long every time I open a file or switch buffers. Any
>> > suggestions? Thanks.
>>
>> Did you file a bug report?
>
> No. I don't  know if this behavior is a bug or just poor performance.
> (Nor do I know, off hand, how to file a bug report.)
>
> This is disappointing. As far as I can tell, Emacs seems to be
> essentially unusable for remote usage. I can't believe I am the only
> one who has noticed this problem. Am I the only one who uses Emacs/
> XEmacs to work remotely over ssh -X?
>

A few things to try ...

1. turn off tooltip mode

2. Try running with -nw to turn off X and only have a terminal UI and
see what the performance is like. this will let you know if the problem
is basic emacs or the X protocol stuff

3. Have you considered running tramp rather than a remote emacs? I've
not bothered with a remote emacs for a long time, preferring to run
tramp (especially with tramps support for remote execution of commands
etc). 

4. Have you experimented with ssh compression? Sometimes you need to try
various values to get the optimal setting for your connection. Most X
protocol packets are quite small and too high a setting for compression
can actaully slow things down. 

5. When I did run remote X based emacs versions, I found using one of
the X compression protocols gave a huge performance improvement. From
memory, the one I used was something like xdcp (X differential
compression protocol or something similar). I believe recent X.org
versions come with support for such protocols. Maybe look at setting
this up. 


HTH 

Tim



-- 
tcross (at) rapttech dot com dot au