Hardware Reference
In-Depth Information
to those used by previous AMD processors. Socket FM2 supports DDR3 memory.
Figure 3.21
illustrates Socket FM2.
Figure 3.21. Socket FM2 before installing a processor.
CPU Operating Voltages
One trend that is clear to anybody who has been following processor design is that the operating
voltages keep getting lower. The benefits of lower voltage are threefold. The most obvious is that
with lower voltage comes lower overall power consumption. By consuming less power, the system is
less expensive to run, but more importantly for portable or mobile systems, it runs much longer on
existing battery technology. The emphasis on battery operation has driven many of the advances in
lowering processor voltage because this has a great effect on battery life.
The second major benefit is that with less voltage and therefore less power consumption, less heat is
produced. Processors that run cooler can be packed into systems more tightly and last longer.
The third major benefit is that a processor running cooler on less power can be made to run faster.
Lowering the voltage has been one of the key factors in enabling the clock rates of processors to go
higher and higher. This is because the lower the voltage, the shorter the time needed to change a
signal from low to high.
Starting with the Pentium Pro, all newer processors automatically determine their voltage settings by
controlling the motherboard-based voltage regulator. That's done through built-in VID pins.
For overclocking purposes, many motherboards have override settings that allow for manual voltage
adjustment if desired. Many people have found that, when attempting to overclock a processor,
increasing the voltage by a tenth of a volt or so often helps. Of course, this increases the heat output of
the processor and must be accounted for with adequate cooling.
Note
Although modern processors use VID pins to enable them to select the correct voltage, newer
processors that use the same processor socket as older processors might use a voltage setting
