Fred Ma wrote: > so it should be at ethernet speeds. If I > start up a vncserver on one sun box, and > connect to it from another sun box, speed is > fine. If I connect to a sun box from a PC
> I thought the bottleneck was conversion from > Cadence's pseudocolor to the PC's true color. > To test this, I creatd a 24-bit true color > VNC server running on Sun. This server would > emulate a PC. Within this server, I launched > a viewer that connects to a 2nd remote > pseudocolor VNC server. Speed of Cadence was > fine, as long as I connect to the 24-bit VNC > server from a sun box. Speed was terrible if > I try from a PC. > The only explanation I can think of for this > disparity in speed is that Cadence uses high > level draw/fill commands to the X server to > update the window and buffer certain images. > One example that supports this is the lightning > fast response when switching between views that > show only cell outlines versus cell details. I'd like to add to the snippets above. Given the above, I think I was wrong in attributing the speed of Cadence to using high-level X window commands. If that was true, then I should have experienced a speed degradation in connecting from sun to sun with VNC. In fact, there was neglegible speed degradation in a complex VNC setup: Cadence opens its tools on a local VNC server with 8-bit pseudo color; from a 24-bit true color VNC server, I launch a viewer to connect to the 8-bit pseudocolor server; from the sun console on the same machine (an native 8-bit pseudocolor display), I launch a vncviewer to locally connect to the 24-bit true color VNC server. Despite 2 levels of VNC links, there was no speed degradation in the Cadence tools. It must be some kind of bottleneck between the sun network and the PC network. The reason why it is not as apparent when using Exceed to connect to sun may be due to high level X windows commands, since Exceed presumably provides X server functionality. So it may be the combination of narrow bandwidth and lack of high-level X windows commands that is slowing down VNC when connecting from PC to sun. Fred -- Fred Ma, [EMAIL PROTECTED] Carleton University, Dept. of Electronics 1125 Colonel By Drive, Ottawa, Ontario Canada, K1S 5B6 _______________________________________________ VNC-List mailing list [EMAIL PROTECTED] To remove yourself from the list visit: http://www.realvnc.com/mailman/listinfo/vnc-list
