Oh, in that case consumer GPUs absolutely suck at FP64, the vendors want you to buy the expensive data-center version. The RTX 4090 has a 1/64 rate when computing with FP64, so only 1.2 TFLOPS!

But from what I can find, the Cell also sucked at FP64, with a rate of 1/10 for a total of 15 GFLOPS (https://en.wikipedia.org/wiki/PlayStation_3_technical_specif... , second paragraph). The 400 PS3 cluster would be 6 TFLOPS or 5x RTX 4090.