RPi 3 has both "full KMS" and "fake KMS" display drivers which support hardware-accelerated GL driver. RPi 4 currently has only "fake KMS". I wonder what difference does it make w.r.t OpenGL support.

Here it is stated that "fake KMS" is useful for video processing because the DispmanX API remains available, which is not the case with "full KMS". Does this affect OpenGL in some way?

1 Answer 1


If GL is off, Chromium is not hardware accelerated. Websites what use WebGL (such as Scratch 3) will be practically unusable, and will use 100% of the CPU.

If GL is on, sometimes problems will result, most recently for me, having Google Maps being garbled. Sometimes there are fixes, sometimes not.

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    Thanks, I have seen your question. It appears that you enabled the fake KMS driver, not the full one. I have an RPi4, so I cannot test full KMS at all. did you try it? Nov 8, 2019 at 14:51
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    According to my tests on a Pi3, Full KMS is no better than Fake KMS. According to Jamesh on the forums, Fake KMS is better supported than Full KMS
    – Botspot
    Nov 8, 2019 at 18:08

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