On 18-6-2010 15:21, Seak, Teng-Fong wrote: > On Thu, Jun 17, 2010 at 10:20, Corne Beerse<cbee...@gmail.com> wrote: >> On 15-6-2010 17:59, Seak, Teng-Fong wrote: >>> It seems that VNC response depends on screen response, ie VGA >>> card's speed. I think VNC only sends screen updates to client only >>> after corresponding pixels are changed on screen (ie in VGA memory). >>> Am I correct? >>> >> This is only true for the native msWindows server side implementation: >> There the vnc-server (the remote side) just grabs the contents of the >> screen-memory and forwards that. Hence, the screen update of the session >> can never be faster/better than the hardware. It's even worse: depending >> on the way the screen-memory is grabbed, the screen update can be realy >> slow. > Is real VNC for Windows such "native ms windows server side > implementation"? And is it possible to know in which way the > screen-memory is grabbed?
See the vnc server properties, tab 'capture method': - Poll for changes to the desktop: just frequently scans the video memory for changes and sends that as updates to the viewers - use vnc hooks to trace changes: vnc-server hooks into the display driver and sends updates as the happen. This might slow down for systems that do verry fast updates. - I'm not sure, but I think the 'poll console windows for updates' is for full screen applications. - I donnot know what 'alpha blended windows' are so I donnot know what this option does. >> To make it even worse: the hardware accelerated video display stuff does >> not use the memory for the screen, it inserts the picture 'on the fly'. >> Hence where the real display shows the movie, the vnc-session shows a >> black square. > I'm not interested in movie related problem, so this doesn't > concern me, correct? It's not only movies, it includes every application that does direct display updates. I'm not sure but I think even a lot of direct-x applications are involved here. >> There are however vnc-server installations that are linked more to the >> display-driver and might do a better job on some side. > Essentially the same question as above: I'm using real VNC for > windows, so how could I know if the server installations are linked to > the display driver or not? For example, see the option 'Use VNC hooks to track changes' in the vnc server capture methods properties. That is the kind of link I mean. >>> I've got a PC whose VGA card is "ATI 3D RAGE IIC PCI". On the >>> screen, the response is quite good. But when used in VNC, the >>> response is horrible -- very slow. >>> >>> Is there any plan to improve this part? Eg using threads if >>> that's not used already. >>> >> Try to find a vnc-server that is tailored to your display hardware. > How? Twiggle with the capture options. On top of that, there are several splits from the origional vnc. RealVNC, TrueVNC, TightVNC and UltraVNC are ones that come to mind. >> On the other hand, using the current installation, twiggle a little with >> the way the screen is updated/captured/refreshed. > I'm already using "Use VNC hooks to track changes". Should I > disable it? But that would mean I have to switch to "Poll for changes > to the desktop". Isn't this a worse option? It sound strange but disabling this setting can speed up things. I had an application that did a complete window update more than once per second. Switching back to the default polling gave me a workable solution. _______________________________________________ VNC-List mailing list VNC-List@realvnc.com To remove yourself from the list visit: http://www.realvnc.com/mailman/listinfo/vnc-list
