GPU

So you fire up a local model and your graphics card starts screaming. Ever wonder why the thing built to draw video games is suddenly the star of running your AI?

Here is the secret. Under the hood, an AI is not really thinking, it is just doing billions of tiny, dead simple multiplications, over and over, to guess the next word.

Your CPU is a genius, but it only has a handful of cores. It grinds through those little sums a few at a time, like one lone worker ticking down a giant list by hand.

A GPU flips that. It has thousands of simple cores and fires them all at once, so those billions of multiplications happen together in one big flash instead of one by one.

So it was never that the math is hard. It is that there is a mountain of it, and doing it in parallel takes you from painfully slow to basically instant. That's why AI needs a GPU. Off the Cloud.