[kde-linux] VNC unacceptably slow for this VNC newbie.

[Duncan]

Pablo Sanchez posted on Mon, 28 Jan 2013 16:52:27 -0500 as excerpted:

> I suspect when you VNC on a LAN, it's not a big deal eh?  The problem
> has to do with how much data you're sending across the wire.  With a
> tricked out WM, it'll be slow.  This is why I suggested twm (and that's
> what I use when accessing a remote box).

I hadn't initially answered as I don't do graphical remoting of any sort 
(and don't use servantware either, as I do not agree to waive my rights 
to damages in case something goes wrong with black-box software that I 
don't have the right to inspect the code of to see what it's doing in the 
first place, so how /can/ I sanely agree to take responsibility for 
damages it might do?... which means I don't get permission from its 
proprietary master to run it, so I couldn't legally do so even if I 
wanted to... thus obviously I don't do MS platforms of any sort either), 
only CLI-based SSH.

But reading the above, three points came to mind, two of which might be 
useful now, the third, perhaps in a couple years.

1) It's worth noting that kde is modular enough that it's quite possible 
to run whatever window manager you like.  It doesn't have to be kwin.  
And FWIW, there's enough running kde with compiz, enough that there's 
integration tools available.  (Altho of course compiz, like most 
compositing window managers, isn't likely to work too well over a WAN 
connection, either.)

It's thus easily possible to run twm or whatever, in place of kwin.  Of 
course, you lose a lot of the fancy effects that way, but it will likely 
be faster.  And of course, it's not going to be as kde integrated.  The 
kde window rules, etc, are all kwin, for instance.  So none of those will 
work, altho a decent window manager should have similar rules that can be 
configured for it.

Of course to switch back to kwin should just be kwin --replace, from 
krunner or a konsole window (as long as $DISPLAY is set, as it should be 
in kde, if you've unset it then use the --display option as well.  I'd 
guess other WMs would have a --replace or similar option, as well, thus 
letting you switch between them, if desired.

2) The question occurs to me, have you tried (keeping kwin but) toggling 
effects off, when you're remoting?  As I said, I don't do graphical 
remoting, so I really have no idea, but if it's the fancy stuff that's 
causing the slowdown, as has been proposed above, toggling off effects 
should speed things up, perhaps dramatically so.  It's worth a try, 
anyway.


3) Of course the X11 protocol was designed to be able to run over a 
network, but all the fancy OpenGL/DRM (direct rendering manager, thus NOT 
remote) stuff, and of course stuff running in VMs, etc, doesn't work that 
way and must be transmitted as bitmaps (tho they can be compressed).  
Since I don't do graphical remoting I haven't kept up with what's most 
efficient at it under which conditions, but I do know that wayland is 
cutting out all the old X11 protocol primitives cruft, and in general, 
will be using the same sort of compressible bitmapped technologies that 
MS and etc have been running for years.  Originally it was slower than X, 
but technology has changed and bitmap/texture compression (among other 
things) is graphics card accelerated these days, so it tends to work 
better in general now, and with wayland, the the technology used will be 
the same, opening up FLOSS graphics to use the same stuff you're finding 
is so speedy for you on the MS side.

But of course that's at least the end of the year for the FLOSS early 
adopters, and from what I've read, kde is going to be six months to a 
year beyond that, so as I said at the top, for kde, we're looking at two 
years out or so, for this one.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman