How many farads do you need for a 5500 watt peak power amp and 600 watt rms 12W6 sub?

I have heard as a rule of thumb that you need 1 farad per 1000 watts, again that's just a rule of thumb and I'm no expert. Seems like overkill to power a 600W sub with that though, you might not need more than a 1 farad since the sub won't be able to handle much more than that