X11 is bandwidth *heavy*... takes over 3 min to launch firefox over a WAN

gnuweenie · 04-03-2011, 12:42 PM

In trying to run graphical x11 applications on a distant remote host, I'm finding that the performance is unacceptable. As a test, I tried launching and quitting Firefox 3.0 over an ssh connection. It takes over 3 minutes just to launch. Here are the results:

Code:

    ssh -X  -c aes128-ctr   myhost time firefox => 3m30.359s
    ssh -X  -c blowfish-cbc myhost time firefox => 3m23.448s
    ssh -XC -c 3des    	    myhost time firefox => 3m33.569s
    ssh -XC -c 3des-cbc     myhost time firefox => 4m0.350s
    ssh -XC -c aes128-cbc   myhost time firefox => 3m26.528s
    ssh -XC -c aes128-ctr   myhost time firefox => 3m11.631s
    ssh -XC -c arcfour 	    myhost time firefox => 3m15.580s
    ssh -XC -c arcfour128   myhost time firefox => 3m30.218s
    ssh -XC -c blowfish-cbc myhost time firefox => 3m12.603s
    ssh -XC -c cast128-cbc  myhost time firefox => 3m44.806s

Using compression only makes a slight improvement. 3 minutes to launch a window is nowhere near acceptable. I also tried using rsh over an openvpn tunnel, where the cipher defaults to blowfish CBC, and comp-lzo is enabled. The result is worse than using ssh:

Code:

    rsh myhost time firefox => 3m42.009s
    rsh myhost time emacs   => 1m45.374s

The bandwidth and latency for this connection is quite acceptable when it comes to text. Using emacs in text mode works fine. X11 is lousy.

What's the solution? I suspect I need to find a lightweight alternative to X11. The end goal is actually to run firefox remotely - don't ask me why.

bluebox · 04-03-2011, 01:09 PM

Quote:

Originally Posted by gnuweenie

The end goal is actually to run firefox remotely - don't ask me why.

Okay, I will not ask ;-)

But a different question ... are you aware that there are textmode-browsers available for linux? Could these be a sufficient replacement for your needs?

In case it is about displaying text and graphics, an encrypted port forwarding of port 80 could do the trick. Your remote host acts as "surfer", unveiling its IP address, but your local station is used to display the websites via local firefox. Your remote machine will act as "proxy", then.

gnuweenie · 04-03-2011, 01:23 PM

Quote:

Originally Posted by bluebox

But a different question ... are you aware that there are textmode-browsers available for linux?

I don't believe Selenium2 will drive any text browsers.

It's looking like FreeNX or x2go may be what I need. It seems these are lightweight X11 replacements.

bluebox · 04-03-2011, 02:50 PM

Just did a little test watching a video over XDMCP on a remote X server, on LAN!

It works, in realtime. X just drops frames, so video stutters.

So there is no reason why starting firefox should take 3 minutes. It should take seconds, just dropping frames.

I suppose, encrypting the whole X data stream is what gives you so bad results, not the performance of X.

AFAIK, whole video buffer frames are compressed, encrypted and sent over the network. So you'll need a good mixture of high compression, fast encryption and low resolution.

Yes, FreeNX may be worth a try. X11vnc comes to my mind, too.

tredegar · 04-03-2011, 03:52 PM

Quote:

In trying to run graphical x11 applications on a distant remote host, I'm finding that the performance is unacceptable. As a test, I tried launching and quitting Firefox 3.0 over an ssh connection. It takes over 3 minutes just to launch.

Firefox over X on my 100BASE-T LAN is instant. There is nothing wrong with X.

You need to look at the performance of the remote server and your network connections. How are you getting an network/internet connection (DSL Broadband, Satellite, mobile phone, dial-up etc)?