From: tym@dibbler.cs.monash.edu.au (Tim MacKenzie) Subject: Re: TERM 1.0.7: How to speed it up? Date: Fri, 30 Apr 1993 01:51:07 GMT
Terry Evans (tevans%sunset.cs.utah.edu@cs.utah.edu) wrote:
>Duperval Laurent (duperval@ERE.Umontreal.CA) wrote:
>:1) I tried runnin an X client (two, actually: ibuil and xcoral). Both came up
>:fine but... sssllllllooooooooooooooowwww. I mean, when I click to get a menu,
>:it can take up to 10 second for the menu to pop up and 15-20 more to execute
>:my choice. This is with a 14.4K modem. I turned off compression and only
>:escape 17 and 19. When I look at my modem, I see it do a lot more sending
>:than receiving. Is this slowness normal or should be doing something else to
>:beef things up?
The X protocol is not the simplest in the world... and if you use complicated
graphics you can have a lot of data transfer for not much drawing. Solution:
don't run X applications over term unless you really, really need to.
Some people have commented on increasing the window size and on switching
off compression within the modem. I do both of these.
Switching off compression in the modem significantly reduces the amount
of buffering done within the modem, so, for instance, the time to echo a
character when in a normal (non-term) session is noticably shorter. Since
term also packetizes its data, the echo response time with term+modem
compression can be most annoying. I also run the modem with error correction
on... this is much better than just relying on term's error correction
and doesn't have a huge effect on delay. Also reduce the modem's packet
size to a minimum.
The second issue is the increase in throughput by modification of the
window size parameter. I use a window size of 10 for 9600baud links, and
3 for 2400 baud. A good way of determining a suitable window size is to
increase it until you get continuous transmission when doing a
tupload. Making the window size too small will cause term to be waiting
too much for ack's and too large will lower performance under transmission
error.