Version: (using KDE KDE 3.1.4) Installed from: SuSE RPMs OS: Linux When i connect to my KDE desktop via VNC (SSH tunneled or not), CPU usage on that desktop soars up to 100%. I haven't looked at the sources, but I wonder if it is possible to reduce the usage of the CPU somewhat. I guess that it required some hacks to integrate VNC into X11 after the latter one started up, and when I use the regular Xvncserver, CPU-usage is also much lower. So is it possible in anyway to better integrate X11 and KDE's VNC server, so that CPU usage drops?
The problem with X11 is that it can't notify krfb when something on the screen changed, so krfb needs to poll for changes by getting the screen content and comparing it to the last snap shot. It tries various ways to improve performance, but in the end a relatively good framerate is only possible by using a large amount of CPU time. There's a X11 extension called XDamage in development that will solve the problem. vncserver is a full X11 server. The networking part runs as graphic card driver, so it does not have these problems.
I've got a hint, that some people might find useful. There is an XFree86 loadable module available which adds VNC functionality to the standard X-server. See http://xf4vnc.sourceforge.net/ for details. This is only useful for your own machines, since it runs systemwide instead of session-wide with KDE's VNC implementation, but it is unbelievably fast.
xf4vnc seems to be very good. Why not integrate it into krfb? Of course, there is quite some effort for setting this up, but the current method could be the default, but if the vnc X module is loaded, this one is used.
*** Bug 80261 has been marked as a duplicate of this bug. ***
The DAMAGE extention should be in the next version of xorg-x11 which will probably be released sometime in August from what I've heard... Will KDE 3.3's Krfb support it for once the new xorg-x11 is released? Even if it doesn't work right, broken support would be better than none at all that way it can be considered a bugfix to get it in for 3.3.1/2
*** Bug 99087 has been marked as a duplicate of this bug. ***
How does one find out if krfb supports the DAMAGE extension? If it doesn't, is it in the feature plan?
If it's horribly inefficient and eating 100% CPU, it likely doesn't support DAMAGE (as it doesn't now). There is nobody maintaining Krfb or Krdc at this time.
Yes, it is eating 100% cpu. I kind of knew the answer to my first question, but was hoping for it to be at least in the feature plan. Too bad no one is maintaining, it's unusable for me. As an alternative to xf4vnc, I tried x11vnc and it works great and it does support the DAMAGE extension.
I don't understand why this bug is marked as resolved ... i still have this problem and I am on kubuntu 7.04 I think it is a very important problem. saying that it will not be fixed is too bad :(
I also don't like this. Why isn't there an option to set the rate manually? That would help a lot!!!