AIUI you can only connect two 3090s at a time with NV link? So you’d only have 48GB of fast combined memory? That’s not tremendously interesting as you’re still limited to the smaller models which, while impressive in their own right, are still IMO too limited to use as your only model.
There are kernel patches to enable P2P communication via PCIE on 3090 which is almost as fast as NVLink for vllm