Asus ESC500 G3 - Manual (Page 30)

Chapter 2: Hardware setup 2-10
Recommended memory configurations
2.4 System memory
2.4.1 Overview
This motherboard comes with four Double Data Rate 3 (DDR3) Dual Inline Memory
Modules (DIMM) slots.
A DDR3 module is notched differently from a DDR or DDR2 module. DO NOT
install a DDR or DDR2 memory module to the DDR3 slot.