Asus P4B - Manual (Page 29)

ASUS P4B motherboard user guide 2-7
2.4.3 Installing the heatsink and fan
The Intel ® Pentium ® 4 478/Northwood Processor requires a specially
designed heatsink and fan assembly to ensure optimum thermal condition
and performance.
The retention module base is already installed on the motherboard.
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.
When you buy a boxed Intel Pentium 4 478/Northwood Processor, the
package includes the heatsink, fan, and retention mechanism.
In case you buy a CPU separately, make sure that you use only Intel
certified heatsink and fan.
Your boxed Intel Pentium 4 478/Northwood Processor package 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.
Figure 2-9 Installing the CPU Heatsink
Retention Module Base
CPU Heatsink