isolates the fluctuating draw of components on one rail from components on the other
was adopted as a strategy from the server system infrastructure spec EPS12V
basically isolates the CPU from instability caused by drives spinning up
on a really well regulated supplies its not that great an issue,
but on supplies of just basic spec especially when they are overtaxed it can be
for foward compatibility you want a supply w\ a 24 pin main power connector
and the spec may soon change again to match the full EPS12V spec
w\ an 8 pin auxillary +12V mobo connector as well
(a double of the current ATX12V 4 pin)