RTX 4090 VS dual RTX 3090 for deep learning build?

I am building a PC for deep learning. I would like to train/fine-tune ASR, LLM, TTS, stable diffusion, etc deep learning models. At the beginning I wanted to go for a dual RTX 4090 build but I discovered NVlink is not supported in this generation and it seems PyTorch only recognizes one of 4090 GPUs in a dual 4090 setup and they can not work together in PyTorch for training purposes( Although I am not sure about that and just …

asr build building deep learning deeplearning diffusion etc llm nvlink pytorch rtx rtx 3090 stable diffusion train tts