[GLLUG] Red Hat, VNC, and remote displays (was: no subject)

[C. Ulrich]

On Tue, 2003-10-28 at 09:49, Edward Glowacki wrote:
> I'm not
> sure how the speed compares to running VNC though, since I haven't tried
> the VNC solution.

When you're running an application across a network, "speed" is almost
always going to be dependent on how much network traffic you're
generating. (I'm going to spell some things out here to clarify my point
and educate others, not to insult your intelligence. :P) 

VNC is best thought of as a computer on one side of the network cable
and a monitor on the other. When you run a program, VNC sends a bitmap
picture of that application (well, the whole desktop, really) down the
wire for display on the user's machine. Network traffic is only
generated when some pixels on the screen change.

With X, you have two parts: a client and a server. The client is the
application being run and the server is the program displaying it. In
this case, the server is the Cygwin XFree86 server. Here, the client is
actually being run on the remote machine, but the interface is drawn by
the XFree86 server. Rather than sending pixels down the wire, the X
client and server send messages back and forth between the application
and the server displaying the interface. 

Thus, the amount of network traffic being generated is highly dependent
on the nature of the application, and X and VNC both generate different
kinds of traffic. Some applications might fare well with X and others
may feel more responsive with VNC. Some might perform horribly on both.
:)

I've always been tempted to try out the Cygwin XFree86 server, but since
my workstation is a FreeBSD machine, I rarely need to display X
applications on a Windows, machine. Much more common is the reverse. :)
Although I'd like to experiment with thin clients running off a central
application server in the near future, so maybe the opportunity will
arise.

Charles Ulrich
-- 
http://bityard.net