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PCB's Introduction to Basic Overclocking


After considerable thought and many, many questions I have been asked and answered, I have finally decided to sit down, and compile much of what I have learned over the years about the fundamental basics of overclocking. What this Guide is, is a compilation of my knowledge on this subject, or at least the fundamentals of this subject. What this Guide is not, is an advanced study of all the available techniques, broken down for all available hardware. I have avoided, to the extent possible, specific information about individual hardware design and settings. The information in this Guide is more universal then specific. Where appropriate, in a couple of sections, I have made distinctions; for example, there are major differences between the way Intel and AMD based systems provided memory management. On the other hand, I have also made every possible effort to follow the "KISS" principle and keep as much in common, and as simple as possible. In some cases, I have sacrificed a small amount of technical precision for practical understandability.

This Guide is not for the advanced enthusiast. It is aimed at the "first timer", a learner who just wants to find out for himself or herself what this subject is all about. So, if you are already an experienced overclocker, you probably won't learn much from this Guide, and in fact, you might find much to criticize.

What is overclocking? It is the totality of methods used by computer enthusiasts, both casual and otherwise, to get as much performance from their systems as possible. Most hardware manufactured today has a safety margin, i.e., the hardware can often perform at levels exceeding the manufacturer's specifications. For example, the P4C Northwood 2.4 gHz CPU was an overclocker's "dream" - as a result of tremendous demand for this excellent CPU, Intel was forced "bin" faster processors, ones that could theoretically perform faster than 2.4 gHz, to the 2.4 bin. The result? Enthusiasts quickly realized that the 2.4C represented a potential bargain. With luck, one might find a 2.4C that could perform far faster then specified, many in excess of 3.0 gHz, or even faster.

With a little bit of luck in your purchasing, some understanding of the techniques of overclocking, and some careful experimentation, it is possible to safely gain added performance for "free" from your hardware. That's the good news.

The bad news? Well, failing to follow reasonable and responsible application of the principles included here, can and often does, lead to catastrophic destruction of your hardware, loss of software or data, or other horrendous results such as walletary dismonetation. There are dangers to overclocking, let no one tell you otherwise. However, do it responsibly and reasonably and most overclocking can be quite safely implemented.

Having said that, don't blame me if something does go wrong. So, here's the legal stuff:, its' leadership and members, and I disclaim any and all responsibility for any and all damage to hardware, software, data, or anything else for that matter, including baldness, psoriasis, sleeplessness, electrocution, etc., that you may experience as a result of following or failing to follow the information in this guide. The responsibility for that, dear reader, is totally yours. If you kill something, that's your problem, so don't claim I didn't give you fair warning. Finally, all opinions in this Guide are those of the author. If you don't agree with me on some point or other, well, don't agree, that's perfectly fine with me.

The Basic Basics

There are three components to basic overclocking: motherboard, CPU and RAM. Other components can also be overclocked, your video card is an example of that. I won't cover those components in this Guide because, in general, I do not recommend overclocking them. Why not? First, there is usually little or no benefit to be derived from overclocking them. Second, overclocking them is fundamentally more dangerous, and much more likely to damage expensive hardware.

Overclocking safely requires a basic understanding of how the motherboard, CPU and RAM work together to perform tasks efficiently. The CPU is the "brains" of your system, the motherboard its' heart and body, and the RAM its' memory. They must work together for any system to function properly, and they must be fine tuned to work efficiently. Mistune them, and either your hardware will fail to work entirely, or else work very poorly. Overtune them, and you may kill your hardware dead as a doornail.

The motherboard has a timing chip on its' circuit board. This timing chip provides all the components with the basic "heartbeat" for the system. All the other system components use these timing signals to determine when, and how, they function. Many components run at a multiple of the motherboard's timing beat, or, in some cases, at a fixed frequency unrelated to the motherboard's signal - AGP, PCI or PCI-E slots are an example of parts that work at fixed frequencies. Peripheral components such as your video or sound cards run at fixed frequencies independent of the motherboard's timing signal; or at least, mostly independent of it.

On the other hand, the CPU and RAM operate at a multiple of the motherboard's frequency. RAM generally operates at twice the motherboard's frequency, or Double Data Rate ("DDR"); and, the CPU operates at four times the motherboard's frequency or Quadruple Data Rate ("QDR"). For example, if your motherboard's frequency, or Front Side Bus ("FSB") data rate is 200 mHz, then, absent the use of other modifiers, your RAM will operate with a frequency of 400 mHz, and your CPU at 800 mHz.

Settings corresponding to all of these items, as well as latency, vDIMM and vCORE (discussed later in this Guide), etc., are made in your motherboard's BIOS. Please read your motherboard manual, it really does have important information you should understand before you start to change settings in your BIOS or elsewhere.