Earlier quoted context omitted.
Do you really need the framebuffer in RAM? Wouldn't that be entirely in the GPU RAM?
To put it in GPU RAM, you need GPU drivers. For example, NVIDIA GPU drivers are typically around 800M-1.5G. That math actually goes wildly in the opposite direction for an optimization argument.
They also pack in a lot of game-specific optimizations for whatever reason. Could likely be a lot smaller without those.