Processor Types and Specifications - Upgrading and Repairing PCs - page 137

Figure 3.51. Active heatsink suitable for a Pentium 4 processor using Socket 478.
Figure 3.52 shows the design used on most Socket AM3+, AM3, AM2+, AM2, FM1, FM2, 940, 939,
and 754 processors, featuring a cam and clip assembly on one side. Similar to the Socket 478 double-
cam assembly, this design puts 75 lbs. of force between the heatsink and the processor. Bowing of the
motherboard is prevented in this design by the use of a special stiffening plate (also called a backing
plate ) underneath the motherboard. The heatsink retention frame actually attaches to this plate through
the board. The stiffening plate and retention frame normally come with the motherboard, but the
heatsink with fan and the clip and cam assembly come with the processor.
Figure 3.52. Active heatsink and cam retention mechanism used on Socket AM3+, AM3, AM2+,
AM2, FM2, FM1, 940, 939, and 754 processors.
Tip
One of the best reasons to use the motherboard-based power connectors for the fan is that most