I'm sure most of you have heard of overclocking and what it does. But for those who don't, here is the idea and what it can do for you. When chips are manufactured, the maker does not test the chips, rather, they manufacture them at the highest speed the core will go at that particular time. They will then make a certain amount of processors at a lower speed by changing it's multiplier setting. This enables them to sell a lower speed chip at a cheaper price without having to redesign the entire chip. What does this mean for you? If you have a chip closer to the bottom of a certain line, I.E. a Pentium III 700, you have a good chance of being able to change the Front Side Bus (FSB) or the Multiplier (AMD Chips only or older Intel) so that the chip will operate faster than what you bought it at. Some examples of this are Pentium III 700s being overclocked to about 900-933MHz and the cheaper Celeron line being able to go from 566 or 600 to 850 or 900 and above. Even if your chip is not at the bottom of the line, there are still possibilities that it will overclock anyway, it all depends on the core of the chip, some chips go way beyond what they are sold as, and some won't budge at all.
Factors
For Intel chips this is a trickier game since you cannot alter the multiplier at all, only the FSB speed. There are two bad things about increasing the FSB speed instead of the multiplier. Number one is that with every 1MHz the bus speed goes up, the CPU speed increases by the multiplier amount, I.E. If the chips multiplier is locked at 9.0, that means every 1MHz bus increment would mean an extra 9MHz on the CPU. This makes it hard to hit that 'sweet spot' (sweet spot being where the CPU is at the highest speed it can go while being stable) because if the CPU jumps 9MHz each increment, you may be jumping 5 or 6 MHz over what it can handle and may have to jump back. Although that's not much of a loss, there is an even bigger concern. If you use non-standard bus speeds (I'll explain these later), the computer may not boot or may have problems because it will stress the AGP/PCI cards and HDs. I'll use PCI is an example, the PCI bus operates at either 1/2, 1/3, or 1/4 of the system bus for it to operate properly. This means that it will always work if your bus speed is 66MHz, 100MHz or 133MHz. But if you are to use a bus speed like 75MHz or 83MHz, this makes things interesting because the PCI bus speed will then run at 1/2 of those speed, which is 37.5MHz for 75MHz, and 41.6MHz for 83MHz (default/proper speed is 33MHz). Although alot of newer PCI cards can handle that, if you have any older devices, this may cause the computer not to boot or crash when it trys to use the device in question. For AMD chips, it's a bit more complex, not only can you change the FSB speed, but with the right technique you can change the multiplier setting as well (more on how to do this later). Standard bus speeds apply to AMD chips as well, except their chipsets have a special CPU <-> Memory bus that will run at 2x the system bus speed, I.E. 100MHz bus on AMD systems is 200MHz between the CPU and Memory, and 133MHz is 266MHz. Also, I will note that it seems retail chips fair better than OEM chips, and chips with the cC0 stepping have attendency to overclock without needing as much voltage as cA0 and cB0 chips. Increasing the FSB isn't all bad, if your looking for the absolute most speed you can get out of your system as long as its stable, this might be the way to go. FSB speeds up everything, the access to the memory, and if it's non-standard, it may speed up or slow down access to PCI and AGP cards. But one thing is for sure, a system running 133MHz system bus is going to be faster than a system running at 100MHz even if the CPU speed is the same in both cases.
System bus speed
PCI bus speed
66MHz
33.3MHz
75MHz
37.5MHz
83MHz
41.6MHz
100MHz
33.3MHz
112MHz
37.5MHz
124MHz
31MHz
133MHz
33.3MHz
140MHz
37.5MHz
150MHz
35MHz
Things you should know...
I'll insert the disclaimer here: We, or more importantly, I do not take responsibility for anything that might happen to you and/or your computer or anything else if you attempt to overclock. Now, on with the rest. Overclocking voids you warranty, doesn't matter how or what you overclock (video cards etc..), so if you're concerned about that kind of thing, this isn't for you. The chances of burning out your chip are rare as long as you don't do anything stupid, but the chance is there if you have to increase your voltage, which alot of people usually have to, I wouldn't go too far from the main voltage. For a chip that runs 1.7V by default, I, myself, wouldn't go any higher than 2V maximum, and that's with damn good cooling. Also, if you're going to use some weird system bus like 75, 83 or 124, I would invest in some cooling for the rest of the system as well. More on the cooling subject in a bit.
A cool CPU is a good CPU!
These days, cooling is no longer an option, it is a must. This part of the article will be brief because there isn't much to say. Now, you can overclock with the standard heatsink + fan that either AMD or Intel will give you out of the box, but you'll only go so far. I recommend you get a cooler by either Alpha or Globalwin, and for god sakes stay away from those Gorbs! (Golden Orbs). And while you're at it, a tube of Arctic Silver as thermal paste. If you don't have a large budget, you can do what I did, get a large generic cooler (worse than name brands but better than the standard cooler by far) and some Radio Shack thermal paste. Other than staying away from the Gorbs, stay away from thermal pads, they aren't worth the money.
The AMD pencil trick
This will only work with Durons and Thunderbirds, sorry all you original Athlon users. The idea behind this trick is to unlock the multipliers. Unlike Intel, who put the multiplier lock inside the CPU core, AMD decided to put the bridges on the top of the chip. Whether this was put there for overclockers on purpose or by accident, we don't know.
I don't know if you can see it, but there is a small gap between all four of those L1 bridges on the chip, you can connect those with any pencil with graphite in it, or a conductive pen. Be careful not to touch any of the bridges next to it at the same time because it can create a short circut. This trick will allow you to adjust the multiplier, making it easier to get the most out of the chip.
Ways to do the overclocking
There are several ways to do the actual overclocking. The first is the more popular way these days, it's to use a function in the BIOS to adjust the FSB or Multiplier. I can't tell you exactly how to do it because it's different for each board. Usually the manufacturer will mention jumperless configuration on their specifications for the board, sort of like Softmenu for Abit boards. Check the manufacturer's website for features and specifications on your board. The second way, which is becomming less popular all the time is by Jumpers or Dip Switches. Alot of newer boards don't use these anymore, but if you don't have a feature like Softmenu in the bios, I would suggest you check your motherboard manual or the manufacturer's website to see which Jumpers/Switches to change. And another way, but I don't really recommend it, is to use a program known as SoftFSB in windows. The reason I don't like it is because it has to do with windows....there need not be another reason to dislike that idea ;p
Conclusion
I've mentioned all you really need to know about overclocking, it's upto you to weigh the pros and the cons against each other and decide if you should do it or not. It may or may not create a large performance gain, it's all upto the chip you have and how determined you are.
If you would like to submit an article. Please send them to warlord@uniball-central.com. If you have images in your document, please keep the images small and correct any spelling or grammar errors you might have before you submit it. Don't forget to title your article and gosh don't forget your name!
News
3li | 
