You'll find that same advice here, posted by One Who Knows.
Code: Select all
vcgencmd get_mem gpu
gpu_mem refers to memory that is addressable from the GPU, which includes the VPU, HVS, legacy codecs (e.g. H264), and camera, and on devices before the Raspberry Pi 4, the 3D system. The Raspberry Pi 4 3D system now has it's own Memory Mangement Unit (MMU) so textures and other GL resources are not allocated from the gpu_mem but Linux system memory instead. This means that gpu_mem can be set to a lower value, so even if you are using the H264 and camera then 128MB will probably be enough. On earlier models without the 3D MMU, you may need up to 256 or 512 in some more unusual cases.
For performance reasons, you should set gpu_mem as low as possible to give the Linux system as much memory as possible. However, setting gpu_mem to too low values may automatically disable certain firmware features, as there are some things the GPU cannot do if it has access to too little memory. So if a feature you are trying to use isn't working, try setting a larger GPU memory split.
Values of gpu_mem over 512 are not recommended, will provide no performance improvements, and are untested.