Please also mention that the reason the Nouveau is slow is not because of incompetence rather it is because nvidia only allows drivers signed by them to be able the change clocks of their GPUs(at least the fairly modern ones) and hence Nouveau can only run the GPU at base clock. This is being rectified now(after like almost a decade iirc) as nvidia is adding their proprietary firmware to the kernal which will then allow Nouveau to control the GPU clockspeed. Also NVK is being developed to provide vulkan support for nvidia GPUs through the open source driver(Nouveau)