alt Hacker NewsWell, you'd use BRAM to store model weights, not fabric. But still, you only get a couple hundred MB for probably close to US $100k per chip.
It's likely that the major FPGA vendors will soon announce parts specifically architected to support LLMs and similar models. But the current generation isn't suitable for that at all.
Would BRAM even have enough bandwidth? The reason I quoted logic cells is because that's the way to get instant throughput, which is practically the only reason to use an FPGA over something like a TPU.