Some users have experienced slow performance when connecting over VNC. This problem has been identified on Matrox G200-based integrated graphics cards, amongst others, which are relatively low spec and only have a small amount of RAM. They are very slow at allowing the CPU to read back the screen capture for use by VNC. Other cards with low memory are also affected.
Workarounds are available.
Replacing the graphics card has been reported to greatly improve performance as has using the generic Windows VGA drivers instead of the drivers supplied with the card. Other users have reported that setting the True Color Depth to 16-bit instead of 32-bit has resolved performance issues.
Additionally, Windows users can obtain a further speed increase by turning off various Windows animations that it performs which helps menu and window-drag responsiveness. To do this in Windows 7:
- Open Control Panel.
- Type "appearance" into the search box.
- Select "Adjust the appearance and performance of Windows" under the "System" heading.
- On the "Visual Effects" tab, select "Adjust for best performance".
If this is undesirable: the worst contributor to performance from the list seems to be "Show window contents while dragging"; most of the performance to be gained can be found by turning this off.
Alternatively, on Ubuntu, see the following post: http://askubuntu.com/questions/673968/regarding-graphical-issues-and-performance-in-ubuntu-14-04-lts-server-with-gui/674656#674656
For general information on ways to improve the quality of your connection, please see our FAQ.