What is CPU Overclocking?

[Jerry]

This is a question for all Computer Engineers. Can someone explain what is CPU overclocking and how is it done?

I came across this term recently and googled for it. I know that it is used to boost the CPU frequency.

Thanks in advance.

Jerry

[pradypop]

All processors(for that matter all ICs) are designed to work at a certain clock speed. If you use any clock above the range than you are over-clocking your CPU.

Now, is it good thing to do? Why do people do it? How to do it? and weather it delivers higher performance?

Its not a good thing to do almost always. People do it to sell off a low-end processor as a high-end one, a marketing trick. A 800Mhz cyrix over-clocked to 2Ghz is available in the market which is passed of as a processor which delivers equivalent of a similarly clocked celeron. That's not true. We can over-clock old P1s an P2s by changing jumper or BIOS settings. For latest boards the frequencies are auto selected. Only manufacturer can over-clock these days.

Over-clocking hampers performance of a processor. By over-clocking there's not enough time available for processor to complete an operation forcing it to redo same operation over and over again until it achieves the result. Thus we bring down the throughput of the processor. It also leads to cache-misses i.e. improper reading of data from system cache.

If its OK to clock Intel 2.0Ghz processor at 3.0Ghz, then you can trust Intel to sell the same processor as a 3.0Ghz processor and not as 2.0Ghz. That sums up things for you.

[Jerry]

It is now evident that overclocking is not good for my processor as I still have an old Pentium-III. Is there a way to verify that my CPU is not overclocked? My friend had assembled it for me.

Thanks for the explanation, Pradypop!

Jerry.

[crook]

As far as I know, the overclocking is simply done by changing the jumper setting. So you could look at the default setting as mentioned in the CPU manual & check the actual jumper setting.

correct me if I am wrong.

Crooook

[aashima]

Originally Posted by pradypop

Its not a good thing to do almost always. People do it to sell off a low-end processor as a high-end one, a marketing trick. A 800Mhz cyrix over-clocked to 2Ghz is available in the market which is passed of as a processor which delivers equivalent of a similarly clocked celeron. That's not true. We can over-clock old P1s an P2s by changing jumper or BIOS settings. For latest boards the frequencies are auto selected. Only manufacturer can over-clock these days.

Overclocking means increasing the working frequency of an electronic component, in this case the processor; using a CPU with higher working frequency means better performances. If you obtain a working frequency of 450 Mhz from a processor with default frequency of 300 Mhz, the performance is the same of that obtained with the version at 450 MHz of the same processor; in a few words, if you achieve a specific working frequency with overclocking, you can obtain the same performance of the version having as default the overclocked frequency.

so there is no harm in overclocking as it provides u with better performance with a low performance chip...

[Neha]

hey, didn't know that earlier...gud

[aashima]

Originally Posted by crook

As far as I know, the overclocking is simply done by changing the jumper setting. So you could look at the default setting as mentioned in the CPU manual & check the actual jumper setting.

correct me if I am wrong.

Crooook

i tried getting sum information on the jumper settings... cudnt get much link of it... cud u be more elaborate crook?

[pradypop]

Originally Posted by aashima

Overclocking means increasing the working frequency of an electronic component, in this case the processor; using a CPU with higher working frequency means better performances. If you obtain a working frequency of 450 Mhz from a processor with default frequency of 300 Mhz, the performance is the same of that obtained with the version at 450 MHz of the same processor; in a few words, if you achieve a specific working frequency with overclocking, you can obtain the same performance of the version having as default the overclocked frequency.

so there is no harm in overclocking as it provides u with better performance with a low performance chip...

There are many factors taken into account before the frequency of a chip is recommended. Most important of these are the internal bus and response times of the chip.

A chip has bus speed of X bits/sec can only ensure that X bits would be successfully transmitted in a second. Any attempt to pump in more data in one second would corrupt the data. Over-clocking precisely does that.

An interrupt that is generated by a peripheral need to stay alive for a while so that the interrupt is detected. If the signal falls too early than the interrupt is not detected and peripheral fails. Over-clocking can do that.

These are only two examples. There can be hundreds of such examples.

If over-clocking can help, I would clock my 3.0Ghz PIV at 3.0Thz and convert my computer into a super-computer. But the bad news is, things simply wont work that way. Working and default frequiencies are two more words in the jargon list. Most engineers who design boards keep working frequiency at the default recommended frequency.

[aashima]

Originally Posted by pradypop

If over-clocking can help, I would clock my 3.0Ghz PIV at 3.0Thz and convert my computer into a super-computer. But the bad news is, things simply wont work that way. Working and default frequiencies are two more words in the jargon list. Most engineers who design boards keep working frequiency at the default recommended frequency.

well there are alwaz certain limitations attached when it comes to enhancement of something and the limitations become even more mandatory when we are dealing with electronic equipments... therz no doubt we can improve our system performance with overclocking but the limitation that rests here is we can overclock a cpu to max 5%. for e.g. a clock with speed of 400mhz can only be overclocked upto 5% to be safe...within this range of overclocking... we can enjoy the +ve results of overclocking otherwise we will have to face the problems enlisted by pradypop...
well a 3.0thz computer cannot be converted to a super computer newaz

[crazy]

Overclocking is the process to speed up of your proccesor. But it is not good for your proccessor. It can harm your hardwares.
Overclocking can done by three ways, by changing jumper or dip-switch settings or by changing some of the chipset features settings in your BIOS.
The most common methods of overclocking your CPU is to either raise the multiplier or raise the FSB(front side bus).

please correct mi if i'm wrong....