Re: [xougen] GPL-ed X compression scheme -- my gaff

[Rich Wareham]

Per Cederberg wrote:
> Thanks for the detailed explanations! I guess I should 
> really try installing NX one of these days... (Not that
> I really need it, but it does sound interesting.)

This is /totally/ unscientific but here are my experiences with NX. Its
not intended as a rant just so people can get an idea of what it's like:

I've got a nice beefy Gentoo box hanging off my University connection
but sometimes I want to access it from a common-room I use a fair
amount. This room is equipped with (by today's standards) pretty poor
Celerons running Windows 2000/NetWare.

I installed NX because a) the Windows client is small and easy to
install and b) because on Gentoo you can type 'emerge
nxserver-personal-server' and magic occurs :)

Upshot: Even with the bandwidth turned up to maximum, NX is /really/
slow on these machines. I now just use the XFree86 pulled out of the NX
client and forward X over ssh (with compression) using PuTTY. Blam!
Everything is snappy and wonderful again [even with KDE + lots of lovely
anti-aliased glyphs to shuttle about the network].

[ Aside: One thing I think Xouvert could /really/ do with doing is
packaging X for Win32 in a nice installer like NoMachines do. Cygwin is
OK but brings in a lot of cruft with it. For people who just want to run
an X-server on a Win32 box to access a remote *nix machine its overkill.
Especially if you have a 50Mb homedir limit :) - A quick Win32 GUI
frontend to the command-line options of XFree86/Win32 would be good ]

Conclusions: Again, totally unscientific but from a quick poke about
with Task Manager, NX's ssh and proxy use a fair whack of CPU time to do
the stream compression and pixmap re-encoding. For thin-clients (which
is mostly what I view these boxen in the common-room as) this places so
much demand on the CPU there isn't enough time to actually make the
X-server responsive(!). I think I agree with Keith P here that a simple
stream compression via ssh -X -C seems to hit a happy medium for
moderate bandwidth connections, even on my girlfriend's 500k cable
connection mozilla is still completely usable with stream-compressed X.

Of course NX is a /lot/ better on sensibly-powered machines over low
bandwidth but how many people run X over dialups anymore?

--
Rich