I’ve got a few 4090s that I’m planning on doing this with. Would appreciate even the smallest directional tip you can provide on splitting the model that you believe is likely to work.
The split is done automatically by the inference engine if you enable tensor parallelism. TensorRT-LLM, vLLM and aphrodite-engine can all do this out of the box. The main thing is just that you need either 4 or 8 GPUs for it to work on current models.
2 GPUs works fine too, as long as your model fits. Using different GPUs with same VRAM however, is highly highly sketchy. Sometimes it works, sometimes it doesn't. In any case, it would be limited by the performance of the slower GPU.
