Why can JAX run fp8 on Nvidia GPUs with sm < 89?

[woct0rdho]

fp8 has hardware support only on GPUs with sm >= 89, such as RTX 4090 or A100. I've seen people trying to run it in PyTorch (e.g., this script) on older GPUs and getting errors. But JAX can actually run it on older GPUs. How is it possible?