Performance

Relevant Configuration

In order to get the best performance out of the system, the most important aspects to consider are (in descending order):

• Picture Encoding
• Colourspace Conversion
• Packet Encoding

For the vast majority of cases, the defaults should already be optimal.

Automated Testing

Please see Automated performance and regression testing

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Below are some more advanced performance related topics:

Stress Testing

To be able to use a single client to create many connections to many servers, or simply to simulate an extremely high performance client, r2482 adds the ability to skip the client code which normally paints the windows. To use it:

XPRA_USE_FAKE_BACKING=1 xpra attach

The XPRA_FAKE_BACKING_DELAY can be used to control how long (in milliseconds) the client waits before responding to the server after each draw packet:

XPRA_FAKE_BACKING_DELAY=10 XPRA_USE_FAKE_BACKING=1 xpra attach

Note: the windows are still shown - just not painted.

Tuning / Pending items

The following mostly undocumented tunables can have an impact on performance and should be investigated more thoroughly under different scenarios:

• XPRA_YIELD - see #181
• Video compression options: XPRA_MAX_NONVIDEO_PIXELS, XPRA_MIN_VIDEO_FPS, XPRA_MIN_VIDEO_EVENTS, XPRA_B_FRAMES, XPRA_VIDEO_SKIP_EDGE, XPRA_SCROLL_ENCODING, XPRA_SCROLL_MIN_PERCENT, etc.. refer to the source code for details.