The RTX 4090 has about the same BF16 Tensor Core TOPs than the A100, assuming 50% MFU (like the A100 40 GB PCIe) it would take 8x longer on 1 RTX 4090 vs 8x A100 80GB SXM, so 12 hours. Datasheet here for the TOPs https://images.nvidia.com/aem-dam/Solutions/geforce/ada/nvid... 50% MFU should be achievable on the 4090.