Debug Flags

Debug command line flags provide additional information about what OpenJFX and sometimes the ability to tweak its behavior.

All of these flags are "unsupported" in that they are officially unofficial. Because they are so useful though, most are likely to remain in the code base.

Unless otherwise listed, the flag should be part of JDK 8 and beyond.

Prism Verbose

-Dprism.verbose=true

Used by prism to report what configuration has been detected. Very useful for identifying startup conditions, such as the hardware detected.

Prism Order

-Dprism.order=sw

Disables any hardware accelerated rending. This should slow down rendering significantly if hardware acceleration is present. Can be used to help identify where a rendering problem is happening. Note that this is actually a list, and the default value normally has the default native accelerated renderer followed by 'sw'.

Prism maxTextureSize

-Dprism.maxTextureSize=8192

Increase the "texture" Dimensions. Images exceeding this limit will not be cached. The example is setting the limit to 8k.

Prism targetvram

-Dprism.targetvram=2G

Increase the "texture" pool. Images and other similar items are cached in a "texture" (used by the GPU). In some cases, a texture intensive application may cause texture swapping as it reaches its internal limit. This command increases the size of the cache pool, at the cost of application memory. Note: some applications will fail if the value is set too high, overpowering the system or GPU memory. The example is setting the limit to 2G.

Pulse Logger

-Djavafx.pulseLogger=true

Enables logging for each of the rendering pulses.

Quantum Verbose

-Dquantum.verbose=true

Quantum Debug

-Dquantum.debug=true