I want to turn my rpi 4b 8gb into a low-quality external gpu. It will recieve instructions through usb3.0 and will render them using its cpu and gpu. I found a library, Swiftshader, that allows cpu rendering when the gpu has to do something it is not capable of. I plan to let swiftshader use all 4 cores, and have a program running at startup that tells it to render and display the data it gets through the usb. If it cannot display with the gpu, it displays it with the cpu. Would this work? I could install a driver on the main computer to tell it to output graphics info through a usb I think. This way, I could give a computer extra graphics power for cheap.