Asus AW171 - Manual (Page 28)

2-8 Chapter 2: Hardware information
2.3.3 Installing the heatsink and fan
The AMD Athlon™ 64 FX and AMD Opteron™ processors require a
specially designed heatsink and fan assembly to ensure optimum thermal
condition and performance.
Follow these steps to install the CPU heatsink and fan.
1. Place the heatsink on top of the installed CPU, making sure that the
heatsink fits properly on the retention module base.
Make sure that you use only qualified heatsink and fan assembly.
The retention module base is already installed on the motherboard
upon purchase.
You do not have to remove the retention module base when installing
the CPU or installing other motherboard components.
Your boxed CPU heatsink and fan assembly should come with
installation instructions for the CPU, heatsink, and the retention
mechanism. If the instructions in this section do not match the CPU
documentation, follow the latter.
Retention Module Base
CPU Heatsink
CPU Fan
Retention bracket lock Retention bracket