Since many in Xtremesystems who don't have a 24pin psu, have been using a pointless 20->24pin adaptor, YES POINTLESS!!!
The boards already have the 4 extra pin connected to the existing 20pin correspondent pins.
The point of 24pin atx is to have more wires to supply the same current, and thus not letting the 12v, for example, overheat.
Well using a 20-24pin is not going to solve that, so...
http://home.mindspring.com/~jjcom/p1.gif
Just take those 4 pins carefully from an old or dead psu, they will be the extra 4 pins.
Then:
- Connect the 5v, 12v and GND, to the correspondent ones in a molex adaptor(this way the current isn't all coming from ATX20pin).
-Connect the 3.3v to a orange 3.3v line from the legacy AT conector, or simply leave it unplugged, since the atx 20pin already has 3 of them.
And you've got yourself a decent 20-24pin adaptor for free, and with 1 hour work.
Post back ur toughts.
Regards.