Hardware Reference
In-Depth Information
CPU Voltage Settings
Another trick overclockers use is playing with the voltage settings for the CPU. All modern CPU
sockets and slots have automatic voltage detection. With this detection, the system determines and
sets the correct voltage by reading certain pins on the processor. Some motherboards do not allow
manual changes to these settings. Other motherboards allow you to tweak the voltage settings up or
down by fractions of a volt. Some experimenters have found that by either increasing or decreasing
voltage slightly from the standard, a higher speed of overclock can be achieved with the system
remaining stable. Some motherboards allow adjusting the voltage settings for the FSB, chipset, and
memory components, allowing for even more control in overclocking situations.
My recommendation is to be careful when playing with voltages because you can damage the
processor or other components in this manner. Even without changing voltage, overclocking with an
adjustable bus speed motherboard is easy and fairly rewarding. I do recommend you make sure you
are using a high-quality board, good memory, and especially a good system chassis with additional
cooling fans and a heavy-duty power supply. See
Chapter 18
, “
Power Supplies
,” for more
information on upgrading power supplies and chassis. Especially when you are overclocking, it is
essential that the system components and the CPU remain properly cooled. Going a little bit
overboard on the processor heatsink and adding extra cooling fans to the case never hurts and in many
cases helps a great deal when hotrodding a system in this manner.
Processor Cooling
Heat can be a problem in any high-performance system. The higher-speed processors consume more
power and therefore generate more heat. The processor is usually the single most power-hungry chip
in a system, and in most situations, the fan inside your computer case is incapable of handling the load
without some help.
Heatsinks
At one time, a
heatsink
(a special attachment for a chip that draws heat away from the chip) was
needed only in systems in which processor heat was a problem. However, starting with the faster
Pentium processors in the early 1990s, heatsinks have been a necessity for every processor since.
A heatsink works like the radiator in your car, pulling heat away from the engine. In a similar fashion,
the heatsink conducts heat away from the processor so it can be vented out of the system. It does this
by using a thermal conductor (usually metal) to carry heat away from the processor into fins that
expose a high amount of surface area to moving air. This enables the air to be heated, thus cooling the
heatsink and the processor. Just like the radiator in your car, the heatsink depends on airflow. With no
moving air, a heatsink is incapable of radiating the heat away. To keep the engine in your car from
overheating when the car is not moving, auto engineers incorporate a fan. Likewise, a fan is
incorporated somewhere inside your PC to move air across the heatsink and vent it out of the system.
In some systems, the fan included in the power supply is enough when combined with a special
heatsink design; in most cases, though, an additional fan must be attached directly over the processor
heatsink to provide the necessary levels of cooling. Case fans are also typical in recent systems to
assist in moving the hot air out of the system and replacing it with cooler air from the outside.
The heatsink is normally attached with clips or snap-in retainers. A variety of heatsinks and
attachment methods exist. According to data from Intel, heatsink clips are the number-two destroyer
of motherboards (screwdrivers are number one), which is one reason the company moved away from
