I wonder what are the practical concerns of loading up an AMD laptop (or I guess one of those mini PCs) with an APU/integrated GPU and allocating 70+GB of ram t

I wonder what are the practical concerns of loading up an AMD laptop (or I guess one of those mini PCs) with an APU/integrated GPU and allocating 70+GB of ram to them as VRAM. Wouldn't that, in theory, be what consumer LLM users want? A mid to low range GPU with tons of VRAM? Or am I missing something here with regards to memory bandwidth? (sort of started this discussion a while back on the localllama lemmy: https://lemmy.ca/post/3910263?scrollToComments=true https://lemmy.ca/post/3910263?scrollToComments=true )