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I have one weak PC (client) but with acceptable 3D performance, and one strong PC (server) which should be capable of running an application using OpenGL twice, i.e. once locally and once remotely for the client. Currently, I ssh -X into it, but the client's console output states software rendering is used and I only get 3 frames per second (fps). Actually, ssh's encryption is not necessary since this is on a LAN, but it's what I already know for remote applications...

So, how can the client performance be increased? My ideas are

  • use hardware acceleration, but the server's or the client's one and how?
  • use something different than ssh

I know, in full resolution and without sophisticated compression a 100 Mbit/s LAN won't make more fps, but it's a windowed application of ca. 800x450, so theoretically up to 12 fps (at 24 bits/pixel) should be possible using uncompressed graphical data. And maybe something better is possible using the client's own GPU or some smart compression.


edit Turns out what I want is basically a local version of what e.g. onlive and gaikai offers. Is there something like this for Linux (and possibly free)?


edit2 VirtualGL looks like the best solution (though currently not working for me), but I wonder if it is possible to do hardware rendering on the client, too

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Follow-up since the the PCs are next to each other anyway and I wonder why not using one PC for two users: Can one PC be used by two users at the same time via dual-monitor? – Tobias Kienzler Dec 30 '10 at 16:27
up vote 5 down vote accepted

You could check out VirtualGL together with TurboVNC should provide you with 20fps @ 1280x1024 on 100 Mbit (see wikipedia).

Do note that it might not work with all applications, it depends on how they use OpenGL.

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+1 this sound exactly like what I'm looking for, thank you! (I'll accept the answer after (hopefully) successful testing) – Tobias Kienzler Dec 30 '10 at 11:37
aww, my Radeon doesn't seem to support pbuffer which is required :( – Tobias Kienzler Dec 30 '10 at 16:23
I have a new PC now which supports pbuffer, but unfortunately vglrun segfaults now. Could this be because the server runs on 64 bit while the client is on 32 bit? – Tobias Kienzler Jan 2 '11 at 10:38
(accepted since the answer is correct and the segfault is a separate question) – Tobias Kienzler Jan 5 '11 at 15:48

That might be true if you have two desktop PC's. But if you have an old WiFi laptop usable anywhere at home (eg Ti5600 with Ubuntu 10.04 as your client, and a desktop PC with a GTX board along with a spare Wi-Fi Router, having a remote OpenGL client seems a good idea.

The problem is getting a remote (server side) OpenGL context. You can run ssh -X on your client. But if you run glxinfo on the remote system, you get your local client, which puts you back where you started. You can set your DISPLAY environment variable to that remote host, and you can use that screen as a second monitor, which still doesn't help.

One other solution is to write your desktop applications so that they can use a remote GLX context:


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Thank you. So is there an alternative for the X protocol to transmit 3D? Sorry, I should have put server and client in quotes, I only meant to have shorter words for the strong and weak PC - both PC's should be used as front-ends at the same time as if they were desktop PCs but with all CPU work and RAM access done by the better PC. The weak PC doesn't have enough CPU power and RAM to run the application itself – Tobias Kienzler Dec 30 '10 at 10:41
Not that I am aware of. The kind of 3D you are thinking of requires a LOT of bandwidth. – Keith Dec 30 '10 at 10:47
that's true :( OTOH, onlive, gaikai and others claim this is even possible for games over the internet... – Tobias Kienzler Dec 30 '10 at 11:01
Ok, I took a look. I don't think they are transmitting the frames that way, either. They are downloading and running local, and only transceiving control and update information, just like existing online games.Even if they did, it would have to be low resolution for high compression. – Keith Dec 30 '10 at 11:08
The way I understand it, they run the game remotely and just transmit a HD stream of the video while receiving keyboard and mouse events. But of course one couldn't transmit 30 fps in HD over the internet without any compression... – Tobias Kienzler Dec 30 '10 at 11:13

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