On my quad core Windows laptop, the attached sample application consumes around 5% of available CPU time when launched as a "native" JavaFX application, and around 25% of available CPU time (that is, an entire CPU core), when launched inside a JFXPanel.

I guess this has to do with non-rectangular clips being used by the application.

To run the sample application inside a JFXPanel, launch it with the "embed" command line argument.

The problem seems to be related to PERF-311 and RT-21740. However, the problem is not Mac specific and is reproducible on Windows, and profiling shows that D3DRTTexture.readPixels is not the main CPU consumer in this case.

The problem affects WebView performance inside NetBeans, see RT-21629.