I want to build a mini-itx computer, but I want to know if I have to buy an special sized (mini-itx) PSU, or if I can go with an standard ATX PSU.
Note: This is the case: BitFenix Prodigy BFC-PRO-300-OOXKO-RP
11 Answer
As per the official specs for your indicated case:
Power Supply: PS2 ATX (bottom, multi direction), PSU cage depth 180mm, max PSU depth 160mm
So no, a special power supply is not needed. An ATX power supply is needed, provided it's not longer than 160mm.
The same may not apply to other Mini-ITX cases, so be sure to check it's official specs.
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