Installing Memory Modules (Dimm) - ASROCK Z270M-ITX/AC User Manual

2.3 Installing Memory Modules (DIMM)

This motherboard provides two 288-pin DDR4 (Double Data Rate 4) DIMM slots.
It is not allowed to install a DDR, DDR2 or DDR3 memory module into a DDR4 slot; other-
wise, this motherboard and DIMM may be damaged.
The DIMM only fits in one correct orientation. It will cause permanent damage to the
motherboard and the DIMM if you force the DIMM into the slot at incorrect orientation.
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