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Overclocking |
Overclocking is a way to speed up a device—such as a
computer's processor—by increasing its clock rate, also known as
frequency. The clock rate of a device represents how many operations
a device can perform each second. For example, a 500MHz (megahertz)
processor performs 500 million operations per second, and a 3GHz
(gigahertz) processor performs 3 billion.
The most common thing to overclock in a computer is, in fact, its
processor. Every instruction the processor executes takes one or
more operations—and, therefore, clock cycles—to complete. By
performing more operations per second, more instructions can be
executed per second and tasks take less time to complete. Sometimes
processors can be overclocked enough to perform as well as more
expensive processors. Overclocking can be a great thing, but it is
not always possible.
In order to be able to overclock a processor, a motherboard must
give the user access to certain settings. OEM motherboards, such as
those in computers from Compaq or Gateway, often have these settings
intentionally blocked out. Since changing these settings without
knowing what you are doing can actually damage the hardware, that is
probably a good thing. The two main settings that are used for
overclocking are the base processor speed (also called bus speed)
and the clock multiplier. The actual frequency the processor runs at
is calculated by multiplying the base frequency by the multiplier.
For example, a base frequency of 200MHz used with a multiplier of 9
gives a final frequency of 200MHz x 9 = 1800MHz. The base frequency
represents the speed at which the motherboard operates and can
transfer data to and from the processor.
Many processors can be slightly overclocked by simply increasing
either the base frequency or the multiplier. Increasing the base
frequency speeds up both the motherboard's data bus frequency and
the processor frequency. For this to be successful, both the
processor and the motherboard must be able to handle the higher
frequencies. There are three possible problems with this method: the
motherboard cannot handle the higher frequency, the processor cannot
handle the higher frequency, or neither can handle the higher
frequency. If the processor cannot handle the higher frequency, the
multiplier can be reduced to still run the bus at the higher base
frequency. If the motherboard cannot handle the higher frequency,
the clock multiplier can be increased instead of the base frequency.
This speeds up the processor's internal frequency while leaving the
bus frequency the same. If both the processor and motherboard have
problems, it is possible that overclocking will not be an option for
that hardware.
A second common thing to overclock is a computer's RAM, or memory.
RAM is where all programs and data are stored while they are being
used by the computer. Increasing the speed of the memory increases
how fast data and instructions can be transferred to and from the
processor. Overclocking memory can be very simple, but also has some
very complex, intricate settings available. To overclock memory in a
basic way, change the operating frequency in the BIOS. That's it. If
the memory can handle operating at the higher speed, it will. If
not, the computer might not boot at all.
If at any time while overclocking a processor or the memory the
computer does not boot, it can almost always be fixed by clearing
the BIOS settings. This is usually done by turning off power to the
computer, removing the CMOS battery on the motherboard, and moving a
jumper on the motherboard to the position to clear CMOS, where the
BIOS settings are stored. Turn the computer back on and default
settings should be used. The battery and jumper can then be
replaced, and slightly less aggressive overclocking should be tried. |
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