Yeah, I agree: I'm actually not expecting it to be easy, and there will certainly be several unknown unknowns we'll discover along the way.

Our process has been, and will continue to be, a sequence of (tedious) R&D experiments where the GPU never behaves as expected when pushed to its limits in ways no-one really tested before (I still have nightmares of the L3 cache cross-IOD bottlenecks on MI300X).

IMHO, we did solve the multi-GPU memory bandwidth scaling problem, and thus the linear scaling of the size of the model towards infinity. But the main difficulties will come from keeping the speed, with steady and continuous memory streaming, while implementing the much more complex architecture of modern frontier MoEs (attention compression tricks, hash layers, routing logic, etc.)