Now the KNC units have been properly tuned ( i use to see over 400 on my kill-a-watt for a Saturn on 0.90 and now see barely 250), do you guys think we can use a CX600 PSU for a saturn with 4 boards, in other words a Jupiter ?
No.
Possibly dependent on the firmware, but it's bronze rated and i wouldn't you'd be redlining more than I'd be comfortable with. Get a Coolermaster V850 they aren't expensive and they are by far the most widely used for the Jupiters.