CPU Overclocking

Overclocking is going mainstream, it seems, among end users. Almost all hardware Web sites discuss the subject, and most make it seem like it’s easy, and that everyone does it. Of course, manufacturers don’t want you to do it to their processors, so you probably won’t find it mentioned in magazines. But, on the Internet, it runs rampant. In many cases, though, you don’t get the real story behind it. Of course, it can speed up the system some, but it also has the potential to do some serious damage to your system.

So, yes, overclocking is a viable option, if you know what you’re doing, and you think the processor can handle it. However, it should be performed by specialized technicians that know what they’re doing. It should not be done especially on systems that are very important in your daily operation. If you use your computer for work or have important data on it, do not overclock. I would never overclock a system I really need.

 

The Overclocking Basics

Quite simply, overclocking is changing the settings on your hardware to make it run faster than the manufacturer intended. All hardware has a certain margin of speed that it was designed to run in. Therefore, overclocking pushes the hardware past its limits. For this reason, you can sometimes run into problems.

Many parts of the system can be overclocked, but the processor is the most common. Most think that it is designed to run at one speed and that it can’t change. But, this isn’t really true. Processors are designed to run at different speeds, just like your other hardware. This way, it can work with a variety of systems. Besides, chips are often labeled slightly lower than their actual speed so that the manufacturer can guarantee it will work at that speed.

The actual speed of the processor is controlled by jumper settings on the motherboard. These jumpers control the bus speed and the processor speed. The reason this is built into motherboards is so one board can operate a number of different processors. Many like to overclock the bus speed, which is basically overclocking the chipset and cards.

 

How To Do It

All over the Internet, overclocking is made to sound so easy anyone could do it. And, in effect, it is easy, but only when it works. Also, you may not have much success. Some chips can be overclocked better than others, and it has nothing to do with the brand. It depends on the chip itself. One guy’s Intel Pentium MMX may overclock better than another’s chip of the same type.

Since system speed is controlled by jumpers on the motherboard, you change the jumper settings on the board and make it think it has a faster processor. For example, if you have a Pentium-200 on a motherboard, you change the settings to make the board think you are running the next fastest Pentium, you could try 233MHz if you’re brave. This works because the chip does not have an inherent speed. It accepts the speed given to it by the motherboard. If you’re lucky, this will work. If it doesn’t work, you may have periodic errors and crashes, or, if overclocked too much, you could damage the chip. A lot of times, you can add extra cooling to the chip to increase the chances of a successful overclocking.

Overclocking the system bus is more complicated because in effect you are overclocking many other parts of your computer. It works the same way: you change a jumper setting. But, the success depends heavily on the chip’s capabilities and the board’s. Boards are designed to run at specified bus speeds with specified multipliers. A multiplier is the number of times faster the processor speed is than the system bus. For example, the Pentium 150 operates with a 60MHz bus speed, therefore it has a 2.5x multiplier. Anyway, motherboards are designed to support certain bus speeds and multipliers, so you can’t exceed these limits. An example: most Pentium boards are made to run at a 66MHz bus speed, therefore can’t operate at 75MHz. On this board, you could not overclock a Pentium-166 to 200MHz unless the board could handle a 3x multiplier (that’s assuming the chip could handle it too).

 

Things To Consider

Before blindly trying to overclock your system, there are issues to be thought out. Mainly, is it really worth it?

Yes, overclocking can increase performance of the system. It makes the processor run faster. And if you overclock the system bus, it helps performance even more. Many choose to leave the processor speed alone, but instead overclock the system bus with a lower multiplier. In many cases, this can yield more performance gain than overclocking the chip speed. But, one thing to consider here is that minor MHz gains are not even noticeable by the user in the real world.

There are risks involved. If you’re successful, your system will be running faster, as little as it may be. But if you’re not, a number of things could happen. It may not work at all, in which case you can, hopefully, just return the settings to normal and try to forget it. In some cases, it may work but crash occasionally or lock up or show other strange errors. You could even lose data on the hard drive. The worst case scenario is that you completely burn up the chip, and that even when returned to normal settings, it refuses to work. This is rare, and usually happens when you get too aggressive in speed hikes, such as trying to overclock a 100MHz chip to 200MHz. Even if overclocking seems to work, there is no telling what harm you are doing to the processor. It may be no problem, but its’ sure to reduce the life of the chip, although you might not care because it’ll be outdated anyway.

Overclocking the system bus is to overclock the other components in the system. For example, many boards are said to support the 75MHz and 83MHz bus speeds while the chipset maker, namely Intel, only officially supports up to 66MHz. So, in effect, you are overclocking the chipset. So may boards “support” these bus speeds, but not really. They are being overclocked. One interesting scenario is the release of the Cyrix 6×86-200. This chip’s speed rating was dependent on the 75MHz bus speed, a speed not officially supported by motherboards of the time. So, manufacturers approved boards that could “support” it. In effect, they were overclocking the Intel chipset on the board.

When you overclock the bus, most other hardware is effected. Therefore there is a risk to every other piece of hardware.

So, not only do you risk the hardware itself when overclocking, you risk the reliability of the system. When errors surface, they will most likely appear to be of another problem, but on an overclocked system, you never really know. Any problems could be a result of the overclocked hardware.

Also, if the system is important to your daily routine, you should not overclock. If you have important data on it, don’t. If your system is under warranty and you’d like the warranty, don’t overclock. If the manufacturer knows or finds out you overclocked it, the warranty is almost certainly void. Finally, if you are a busy person, you probably don’t want to overclock. Problems may surface and demand your time and you won’t have time to fix it.

It could be wiser, if you want speed, to just buy a processor rated for that speed. This way, you don’t risk the money involved, and don’t have to pump more money into the system for repairs or more cooling.

Ludo Morgan
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