How to Overclock a CPU
Every machine needs tuning and modifications, if it has to go beyond its current performance levels. Overclocking your CPU is a similar procedure, which can boost its performance to never before attained levels. However, right at the start, before providing you with tips on CPU overclocking in BIOS, you need to be warned about the dangers of this procedure. If the procedure is executed without a proper study of all the complexities involved, you may end up destroying the chip and computer motherboard entirely! Just like tuning a motorcycle or car engine to surpass its inherent 'safe' performance limit is dangerous, so is CPU overclocking. So it's advised that you carry out this procedure on old machines and old components first till you get a hang of it.
Basics & Preparation
A lot of computer users tend to be unaware about the fact that a computer processor's specified maximum clocking frequency can actually be overridden to derive greater computer performance. This is achieved through BIOS level modifications in CPU core voltage, processor internal multiplier and computer memory bus frequency, which leads to the attainment of a greater clocking frequency. While the average user may not be interested or may not even benefit from this procedure, it is an interesting technique to learn for computer geeks, if they want to understand how computer really work at the base level. The basic idea of overclocking can be summarized with the following equation:
Computer Processor Clocking Frequency = (Internal Multiplier) x (FSB frequency)
Here the clocking frequency is the operating frequency of the processor which is usually specified in Gigahertz (GHz), internal multiplier is a preset value of the processor, which is a ratio of the internal clocking frequency with the external clock frequency and front side bus (FSB) frequency is the operating frequency of the bus channel that transmits data between the computer memory and processor. For example a CPU with an FSB frequency of 200 MHz and a Internal multiplier - 15x will have a clocking frequency of 15 x 200 MHz = 3 GHz.
To increase the clocking frequency of the CPU and raise it beyond its set limits, or overclocking your CPU, either the internal multiplier or the FSB frequency needs to be increased. Most chips have a preset internal multiplier, which cannot be changed. The only feature that can be modified is the FSB frequency, accompanied with an increase in operating voltages of the motherboard.
As a result of greater core voltage being fed in, the heat output of a processor increases, which necessitates that a cooling mechanism, along with extra heat sinks be fitted on the computer motherboard. To provide greater voltage to computer hardware components, it's necessary that you may have to install a SMPS with a higher power output.
Besides devising a method for cooling the computer motherboard and installing a higher wattage SMPS, you will have to first check whether it's possible to overclock your motherboard beyond its set limits. You need to check out which computer processor is installed on it and what are its voltage and clocking frequency values. Depending on what kind of processor you use (Intel or AMD), the strategy for overclocking will vary. Conduct processor specific research and check if your motherboard BIOS supports it. Most OEM motherboards supplied by Intel don't allow it.
To check if the motherboard supports overclocking, open the BIOS settings and look for 'Voltage and Frequency Settings' of the CPU. If it is allowed, you will have access to modify these settings. If they are not present, then the motherboard doesn't allow it.
How to Overclock a CPU in BIOS or By Manipulating Hardware?
First step is setting up extra heat sinks and cooling mechanism in the motherboard. Check out sites on the Internet which can guide you in this regard. Also install a more powerful SMPS which can supply greater power output.
Conduct a benchmark and stress test of the CPU, using software programs designed for the purpose, before you begin overclocking. There are two ways you can change the clocking frequency. It is either through BIOS or through the hardware.
For hardware level manipulation, refer to your motherboard manual and locate the jumpers used for clocking speed selection and resetting the BIOS to default settings. Using the information provided in the manual, change the jumper positions to get a desired CPU clocking frequency and internal multiplier value. Make the changes and reboot the computer to see if the system is working stably. Conduct benchmark tests to monitor performance enhancement. Keep modifying the FSB frequency and internal multiplier value using jumper settings till you get a stably running high performance system.
The second overclocking technique is based on manipulation of BIOS settings to change FSB frequency and internal multiplier, along with a fractional increase in voltage values provided to the system.
Keep making incremental changes in these parameters and rebooting the system to run stress tests and gauging performance. In case the system overheats and shuts down, use the BIOS reset jumper to restore to default settings. Keep checking the CPU health status and if it rises close to 70 Celsius, it is time you stopped increasing the voltage and settle for the last bootable configuration. This method is pretty much trial and error and there is no way of knowing which voltage and frequency combination will provide you with a high performance system. Make sure that you research the whole thing thoroughly before you go ahead.
You can derive a marginal increase in performance of your PC and take it to the limits of its abilities by overclocking it. This can be extremely helpful in case of CPU intensive applications like large simulations and video editing. However, with modern Intel core i3, i5 and i7 line of processors, there is an inbuilt Turbo Boost technology which can raise the clocking frequency beyond the base frequency when need be. As discussed before, this technique is not a perfect science. Rather, it's a trial and error procedure which takes a lot of time and patience to get right. Make sure that you have studied the procedure thoroughly and thought about all the things that could go wrong, before going ahead.
