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Slow performance and troubleshooting

Performance issues

Forms can be slow, and this is especially noticeable if you are using text input on a slower system. If you find that forms are too slow, you can do a number of things:

  • Switch to the legacy backend and set Double buffering to 'no' in the backend settings.
  • Switch to the xpyriment backend and set OpenGL to 'no' in the backend settings. Important: This disables hardware acceleration and decrease the precision of the display-presentation timestamps.
  • Reduce the number of elements on the form. The speed with which the form is rendered is directly proportional to the total surface of all its elements.

Troubleshooting

  • If you are using the legacy backend, you may find that the forms do not show: The screen is black, except for an occasional flicker when you click the mouse. This issue can be resolved by setting Double buffering to 'no' in the backend settings.
  • If you are using the legacy backend, you may find that the mouse cursor is not visible. For a workaround, see:
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