Monday, December 25, 2000		Lead Article

Though the purpose of overclocking could vary from having fun to getting more performance from your computer, it must be remembered that overclocking is not an easy task and requires a good knowledge about the working of a computer and technicalities about the processors, motherboard etc. Amateurs should not try overclocking as this could result in serious damage to your processor, says Vipul Verma

Yeh Dil Maange More! Well, this is not only a jingle for Pepsi, but also a natural urge for enthusiasts in every field, including computer enthusiasts. The fun of getting more while paying less drives many persons in the world of computers to explore and enhance the value of their PC. Overclocking thus becomes a natural consequence. What is overclocking? Making the processor run at a higher speed than it was intended to by the chip manufacturer is called overclocking.

The speed of any processor is determined at the time of its manufacturing. Depending on its capabilities, the processors are set at speeds at which they are expected to perform. But since the processing speed could vary from situation to situation, processors are normally rated marginally lower than their capacity. It is this slight underrating that the overclockers exploit to increase the speed of their computers.

There could be several ways to overclock your computer and could be as simple as changing a few jumpers or dipswitches on your motherboard or even making a few changes in the system bios. But depending on your motherboard manufacturer, it could be as complex as changing bus speed, clock multiplier or even the processor supply voltage.

Though the purpose of overclocking could vary from having fun to getting more performance from your computer, it must be remembered that overclocking is not an easy task and requires a good knowledge about the working of a computer and technicalities about the processors, motherboard etc. Amateurs should not try overclocking as this could result in serious damage to your processor. Readers wanting to try this may do so only under expert guidance.

If done with some expertise, there is not much risk involved in overclocking, but without it, running your processor at levels higher than it is intended to can cause Electro Migration. This, in turn, could destroy your chip as it puts additional strain on the MOS and dielectric ions within the CPU. The electric current then makes the electrons impart momentum to the ions, resulting in generation of a force called Wind Force. This moves the ions in the direction of the electrons and a physical change in the shape of the material takes place resulting in permanent damage to the chip.

It is also possible that the processor may not suffer complete damage immediately. It may weaken it and its life span may get shortened. Normally, the life of a processor is 8-10 years based on normal usage. Under better condition of usage, the life of the processor could increase. By unhealthy overclocking, the life of the processor can be considerably shortened as it has to run at a higher temperature. The higher temperature generated due to overclocking can partially be taken care of by installing a good CPU cooling unit.

Normally, CPUs runs between a temperature range of 100 and 140 degrees Fahrenheit. A CPU is designed to withstand heat up to 180 degrees Fahrenheit. So if you do decide to make an attempt at overclocking, the first thing which needs to be taken care of is the cooling of the overclocked CPU by using good quality heat sinks and fans. Also insist on a fan with higher RPM. There are several other things like thermal compound layering between the CPU and the heat sink that can be used to keep the system cool.

The second basic requirement for overclocking is a good and standardised motherboard. The use of sub-standard motherboard in overclocked mode can cause your system to hang as the motherboard may generates some signal errors. You can determine the capabilities of your motherboard from its manual. The motherboards with higher bus frequencies like 75 MHz and above are considered appropriate for overclocking. However, it should also be supported by corresponding voltage limits.

Methods of Overclocking: There are several methods of overclocking your processor ranging from simple to complex ones. However, given the circumstances, the best method for improving system performance through overclocking is by increasing the bus speed on the motherboard. But if the motherboard doesn’t support a higher bus speeds or if your RAM or any other PCI cards are not compatible with higher bus speed, then you can change the clock multiplier for boosting the performance of your computer. However, there is a word of caution here — if you change the clock multiplier you will gain in speed but may lose performance. Even decreasing bus speed and increasing clock multiplier will result in loss to performance. For example, if you change the running speed of your processor from 166 MHz @ 2.5x66MHz to 180 @ 3x60MHz through jumper setting or setting dip switches, it will actually decrease the computers performance. However, in case you are able to increase the bus speed with the speed of the processor, the overall performance of the computer can be boosted. So the basic methods of overclocking are:

Changing the Bus Speed: It is a good method to overclock your Pentium, 6x86, or even an AMD processor. Normally, the internal clocks of all these processors run at different speed than the external clock or bus speed. The external clock is the speed at which the cache and the main memory run and when divided by two it gives the speed of the PCI bus. You can change the bus speed by looking at the details of your motherboard for External (BUS) Frequency Selection. Here you will find the jumper settings and also dipswitch settings which can be changed to get the desired bus speed given the maximum the motherboard can support. In certain motherboards, these settings can also be changed in the BIOS set up and the bus speed can thus be boosted.

Changing the Clock Multiplier: You can also overclock your processor by altering the clock multiplier. Normally the Pentium CPUs supports the following multipliers: x1.5, x2, x2.5 and x3. Whereas Cyrix/IBM 6x86 CPUs supports x2 and x3, but the M2 supports x2, x2.5, x3, x3.5 clock multiplier. All these settings can also be changed by either jumper settings or by dipswitches, either of which would be present on your computer’s motherboard. The details are also mentioned in your motherboard manual.

Changing the Processor Supply Voltage: Changing processor supply voltage can be used in conjunction with other methods of overclocking. This, however, is one of the most critical and also the most important part of overclocking. Generally, the changing of processor’s supply voltage from STD to VRE voltage can lead to successful overclocking. However, unless done carefully, high voltage can actually destroy your processor.

So, overclocking you computer could be fun if you manage to boost your computers performance. But be careful, some unethical vendors overclock the processor and sell the machine with a higher price tag. Some utilities like the Processor Frequency ID Utility on the Intel site let you determine whether the Pentium processor is overclocked.