The R500 series of GPUs are mid 2000s ATI GPUs. On Linux, they are handled by the r300 driver.
Presence in collection
- tegu (ATI Mobility Radeon X1300)
GTK4 applications don't render
First, try starting the GTK4 application through a terminal. If you see output about an r300 FP compiler error, inability to allocate, and that a dummy shader will be used, you will need to start the application with LIBGL_ALWAYS_SOFTWARE=1 for the application to render. Do note this disables hardware acceleration.