[D] Training LLM with A100 vs 4x4090?

I have to make a choice between A100 (80Gb) vs 4x4096 (92GB).
I am looking to train a 7B model. Looks like 7B model will take 55 GB (using Adam as optimizer).
So, if I have a 4x4096 GPUs, is that even enough? If I train using DPO or rhf, which will have two models, will that make the GPU 3x?

Which one should I use, A100 or 4x4096?
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