2.5" uses 5V but 3.5" uses 12V so is it ok that the two share the same cable from PSU. PSU would be a S12II 620.
Similiar thread but I'm abit confused: http://www.tomshardware.com/forum/245289-32-connecting-sata-disk-desktop-internal-sata
Similiar thread but I'm abit confused: http://www.tomshardware.com/forum/245289-32-connecting-sata-disk-desktop-internal-sata