The ATX form factor measures up to 305 × 244 mm, and the E-ATX form factor up to 305 × 330 mm. The motherboard Gigabyte Z690 Aero G measures 305 × 244 mm, therefore it is made in the ATX form factor, and it has 9 mounting holes for installation in a case. Note, however, that one of the nine mounting holes is covered by a heatsink for the M.2 slot.
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