Ranting on the X protocol

Posted Jun 2, 2010 16:21 UTC (Wed) by rsidd (subscriber, #2582)
In reply to: Ranting on the X protocol by martinfick
Parent article: Danjou: Thoughts and rambling on the X protocol

As for VNC, it never seems to work as well for me, last time I tried it, youtube videos were all blue...

And youtube video works over X11 forwarding? How about the audio, over either X11 or VNC?

VNC works well for the cases it's meant for, and on slow links it's much faster than X11 forwarding.

Ranting on the X protocol

Posted Jun 2, 2010 16:37 UTC (Wed) by martinfick (subscriber, #4455) [Link]

I am not sure if your questions were aimed at me? What do you mean by X11 forwarding? (via ssh?) Via normal X11 (non ssh) the videos are just fine (not blue). I don't work remotely over slow links, I use X on my home LAN only. As for sound, I don't use any X11 or VNC features for it, I just use PA and multicast so I can hear what I want anywhere on my LAN, works fine. Again, I am not criticizing VNC, I think it is great too, but it is different than X and not a good substitute in all use cases. And, as with most software, it helps to have multiple solutions available since sometimes they don't all work perfectly.

Ranting on the X protocol

Posted Jun 2, 2010 21:36 UTC (Wed) by daglwn (guest, #65432) [Link] (2 responses)

VNC works well for the cases it's meant for, and on slow links it's much faster than X11 forwarding.

That's not been my experience at all. VNC has always been slower than just running windowed emacs over the X protocol, for example.

Ranting on the X protocol

Posted Jun 8, 2010 20:23 UTC (Tue) by nix (subscriber, #2304) [Link] (1 responses)

Yes, with things that don't use Render much, or which render mostly monocoloured backgrounds (like most text editors), VNC's simpleminded 'just transmit giant bitmaps' scheme is intolerably inefficient and laggy. It's laggy even over a gigabit network... tightvnc makes it a bit better, but not much.

Apps that render backgrounds which consist of repeating elements can use Render to transmit those elements only once.

With things that have heavily coloured/textured backgrounds which are different at every point, maybe, just maybe both would be equally efficient... although surely you'd send that to the X server as a pixmap.

Can anyone think of *any* application (other than e.g. talking to Windows systems on the far side, or handling disconnected operation, neither of which X was designed for) for which VNC is preferable to X? I can't think of any.

Ranting on the X protocol

Posted Jun 8, 2010 22:15 UTC (Tue) by rsidd (subscriber, #2582) [Link]

Here's one: a slow network connection with latency (eg, connecting to office from my home). VNC is usable, X11 forwarding is not. I am willing to believe that X11 beats VNC on gigabit networks. And, of course, if the connection goes down you lose nothing (except time). You seem to be saying X was designed for LANs (where disconnected operation is relatively uncommon) and not wider networks. If so, that's another argument for VNC.

Ranting on the X protocol

Posted Jun 3, 2010 0:12 UTC (Thu) by agriffis (guest, #10251) [Link]

Regarding youtube, it works fine over X11 on a gigabit LAN. But a better example is mplayer which runs 720p video dandily using Xvideo over the network, and audio syncs well using pulseaudio. I haven't tried VNC and don't know how it would do for that, but I run thin clients upstairs to a server in the basement and the system works great, with one notable exception: mythtv-frontend. Unfortunately the only way to make this work on the thin client is to run it locally, but the thin client doesn't have the horsepower to do so.