Re:Intel announces Arc B-series "Battlemage" discrete graphi...
by amelius on Tuesday December 03, 2024 @05:29PM
(#42312303)
> Splitting the model up between several GPUs would add a third much worse bottleneck – memory bandwidth between the GPUs.
What if you allowed the system to only have a shared memory between every neighboring pair of GPUs?
Would that make sense for an LLM?
Re:Intel announces Arc B-series "Battlemage" discrete graphi...
by imtringued on Wednesday December 04, 2024 @06:03AM
(#42316359)
At least for LLMs and transformers this isn't relevant. Having 8x the chips and 8x the memory bandwidth is always better. Interchip communication for matrix multiplication against a constant left matrix with a tiny right matrix isn't bandwidth bound, only latency bound.
Splitting the model up between several GPUs would add a third much worse bottleneck – memory bandwidth between the GPUs. No matter how well you connect them, it'll be slower than transfer within a single GPU.
Still, the fact that you can fit an 8× larger GPU might be worth it to you. It's a trade-off that's almost universally made while training LLMs (sometimes even with the model split down both its width and length), but is much less attractive for inference.