Why it fries? doesent understand why ?
you mean the higher possible output on an ATX Powersuply i gues ?
This is no problem ... The Current (A / Ampere) are not "pushed" they are taken by the consumer...
It doesent matter if the Suply has 12V and 1000A ... the Cube will only use 10 or to be more accurate 8 A from the suplys this is how Electric Power Works.
trust me its my job ...
br Caeruleus
Is yours working well?
Yes Since 9 Hours now.
I also cant imagine why it should not ATX Power Supplys are much more stable in Voltage so there is no much +/- from 12 V and as said the maximum current is irrelevant its only the maximum from the power supply.