Heat, Cooling and Voltages
As we stated in our Intel overclocking review all CPU's run hot. AMD Athlon and Duron CPU's run hotter than Intel CPU's are require greater cooling to run at the same speeds, however this doesn't deter the clocking ability of the AMD K7 Family of CPU. When you overclock the CPU you cause the core of the CPU to run faster than it was originally designed to do and this causes more heat, ergo, you need more cooling, the cooler you can get your CPU to run at, the more change you have of overclocking it. The reason we cool CPU so much is that heat is what causes the CPU to crash and not respond. Heat gets between the components in the CPU and prevents a good electrical currant from flowing and intern causes the CPU to breakdown and stop responding. If we are able to use a larger cooler to extract more heat then the components of the CPU can then receive the currant more efficiently and overclock even more. When you have reached the limit of what you can overclock the CPU to on the default voltage this doesn't signal the end of the overclock for only the components are having a hard time but the core can still handle more speed so how to we get a clearer electrical signal? Increase the voltage supplied to the core of the CPU. Voltage is one of the most important features that will determine a successful overclock. When you increase the voltage you also increase the amount of heat that the CPU produces and more cooling is again required. When the CPU is made they are given a default core voltage. Slot A AMD Athlon Classics work on a 1.6v core. Socket A and Slot A AMD Athlon Thunderbirds use a 1.7v core. AMD Duron CPU work on a 1.5 or 1.6v core. When changing the voltage to help your overclock you must use common sense and know when enough is enough. For your reference here are some safety levels for the AMD K7 Family:
- Slot A AMD Athlon Classic: Max of 1.9v
- Slot A and Socket A Athlon Thunderbirds: Max of 1.85v
- Socket A AMD Duron: Max of 1.85v
These levels are just a safety guide, you can increase the voltage to a higher level if you wish but the likelihood of damage to the CPU becomes greater. Today most motherboards provide BIOS control over the core voltage of the CPU so you don't have to open up your case and fiddle around with jumpers or dipswitches.