AZDO is general term for techniques that reduce driver overhead, not limited to persistent mapping. OpenGL drivers have a habit to try to second-guess the appl

AZDO is general term for techniques that reduce driver overhead, not limited to persistent mapping. OpenGL drivers have a habit to try to second-guess the application (though this depends on the driver, eg. Nvidia guesses a lot, Mesa not so much), but passing/not-passing GL_CLIENT_STORAGE_BIT to glBufferStorage should decide whether buffer should reside in CPU/GPU side memory. In D3D11 directly mapped GPU memory is known as D3D11_USAGE_DYNAMIC.