I regularly need to connect from a Windows box to an OSX box over VNC.

OSX has VNC built-in as part of its "Screen Sharing" tool, but for some reason, it's much faster to connect from OSX to OSX or from OSX to Windows than it is to connect from Windows to OSX. (I use UltraVNC on Windows.) Windows to OSX connectivity is almost unusably slow, even when the two boxes are sitting right next to each other, plugged into the same router.

How can I improve performance in this case? Should I explore alternate Windows clients? Alternate OSX VNC servers? Should I use some other screen-sharing tool instead of VNC? (If so, what?)

(Note that this question is more specific than other more general questions.)


OS X Leopard with its own ScreenSharing client, connecting to another OS X native screen sharing server, does some negotiation on colour depth, etc., so it's transferring less data.

(You can see this effect exaggerated if you connect to an OS X system from Windows using the RealVNC client over a higher latency connection. It will take a long time to build up the screen output.)

I couldn't find a way to make RealVNC request a lower colour depth so what I did, to work around this, was run a copy of VineServer on OS X with the '-maxdepth 8' option (and '-rfbport 5901' to run it as an alternate server), and connect to that when I connect long distance (which I always do through an SSH tunnel, before anyone states the obvious.)


I've switched from UltraVNC (back) to RealVNC, primarily because UltraVNC was not handling my multi-monitor server right.

  • I also switched to RealVNC as it provided the best speed. I'm now running 1080p over a 100 Mbit network without problems. OSXVnc was too slow, as was Apple Screen Sharing. – Adam Lindberg Apr 30 '11 at 19:22
  • 3
    Did you use RealVNC on both client and server side? – thomthom May 27 '12 at 18:59

I found switching to Vine Server rather than the default Apple one made a huge difference to performance.


I experienced the same thing, but could not get UltraVNC or TightVNC to match the performance I expected. I was tipped of TeamViewer and it worked like a charm. The setup configured the computers for access and after letting them accept connections over LAN I got speedy remote control with full colours.

  • Do note the price of those products went from $0 to $750 – Joseph Lennox Mar 3 '15 at 23:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.