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| Overclocking guide by sepul   | Type: text/plain | Size: 10k |
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|                  Written by Chris S                          |
|                     A.K.A sepul^                             |
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	Save to FreeDrive This article was originally written by Shrishail 
Rana and was dated and full of irrevant information, so I re-vamped the whole 
thing. This is written as a guide only, your circumstances may vary and 
I take no responsibility what so ever for any damage of any kind.

A step by step guide to overclocking.


1. What is Overclocking ?
=========================

	Overclocking originally called ‘performance margining’ is the art 
running your processor, or any other component, at a higher frequency than 
it is rated for. The whole concept behind overclocking is to increase the speed 
( Mhz ) of a processor to achieve a faster system. This extra speed does 
come at a cost though, in terms of heat and you usually have to buy something 
( cheap ) in order to not risk the life of your CPU. If your CPU does become 
too hot due to overclocking or any other factor it may not continue to work 
at its rated speed or may not work at all. Play it safe and don’t try 
anything stupid and you should be fine.


2. Basics of CPU frequency
==========================

	Two variables determine the speed at which your CPU runs: the Front Side Bus
(FSB) and the clock multiplier. By manipulating these variables you determine 
the CPU's clock speed.

For example a PIII700’s settings are as follows: 7x100=700.


3. Overclocking Morale
======================
	
	If you are unwilling or afraid to overclock your CPU, there is no reason 
to annoy other people with your opinion. Just because the CPU manufacturers have 
an opinion on overclocking does not make it the right one. People who are 
overclocking their CPUs choose to see it differently and are benefiting from 
their opinion. As long as there is no sentence against overclocking, we are 
not doing anything against the law.  


	The main idea behind sensible overclocking is simply to use your brain. 
If you want to successfully overclock your system without any loss in 
reliability, you will have to take care of proper cooling, do decent testing, 
and stay within the bounds of common sense. Don't try to overclock 
a Athlon 500 to 1500 or anything crazy like that. Just use your brain!


4. Why not to Overclock
=======================

	Although there are zillions of tales of damaged CPUs and other system 
components, in most cases overclocking is completely harmless There are, 
however, a few things to take into consideration both fatal and non fatal :

	The non-fatal one is due to timing. Processors are designed and tested so
that their internal parts will all be ready about the same time, according to 
specifications published by their manufacturer. As the heat of the processor 
increases above specifications, the internal paths slow down. Some paths slow 
down more than others, and eventually there becomes a significant difference 
between when something is expected to happen and when it actually does happen. 
At this point you may get false information (such as 0+0=1), system lock-ups, 
or spontaneous resets. This behavior is usually a signal for you to decrease 
processor speed or temperature

	One fatal possibility is called electromigration. Overstressed ICs can 
be slowly destroyed by electromigration. The combination of heat and electric 
fields cause metal atoms to wander around under the passivation layer.

	Electromigration takes place on the actual silicon chip of your CPU in 
areas which operate at a very high temperature, and can cause permanent damage to 
the chip. Before you start to panic, you should first realize a few things. 
CPUs are designed to run at temperatures between -25 and 80 degrees Celsius. 
To give you an idea, 80 degrees Celsius is a temperature that nobody is able 
to touch for longer than 1/10 second. I have never come across a CPU at this 
temperature. There are plenty of ways to keep the CPU case at less than 50 
degrees Celsius which increases the probability of keeping the chip inside 
at less than 80 degrees. Also, electromigration does not immediately damage 
your chip. It is a slow process, , which more or less shortens the life span
of a CPU running at a very high temperature. A normal CPU is meant to live 
for about 10 years. However, in ten years nobody is going to be using a CPU 
with today's technology. If you want to be kept free from this electromigration 
scare, you have to do as much as possible to cool the CPU. Cooling is the number 
one requirement in overclocking!!

	Due to electromigration CPU tend to grow little whiskers at any sharp 
corner or irregularity along a trace. Whiskers at different potentials tend to 
grow towards each other, much as stalactites grow towards stalagmites in a limestone 
cave,because the sharp point accentuates the potential gradient. In a cave, 
limestone columns eventually form from floor to ceiling.. On a chip, you get 
a short circuit.  

	Heat is only a secondary factor in electromigration. The primary factor is 
current density in the presence of an electric field. In most digital ICs, the 
internal clock signal is distributed by a conductor, usually aluminum, which 
is sized carefully for its load. If the clock switches more often than the 
designer sized it for, then the clock "trunk" is overloaded and subject to 
premature failure due to electromigration.

	The other fatal possibility is simply burning out the bond wires that run 
from the pins on the outside of the package to the silicon die of the processor. 


5. Overclocking goals
=====================

There are three ( 3 ) main goals behind overclocking:

* Improved system performance
* System to be just as stable ( or more so ) than it always has been
* To keep your CPU alive


	The best way to improve system performance is with the FSB, and if 
you’ve got a Celeron PII, PIII this is your only option for overclocking as 
Intel has put a multiplier lock on these processors. AMD has also put a ‘lock’ 
on their latest CPU’s ( Duron, ThunderBird ) but it can be overcome by joining 
the L1 bridges on the CPU.

	If you’re planning on FSB overclocking it’s generally a good idea as 
it speeds up everything else on your system  because as you raise the FSB of 
your CPU everything else that uses a divider of this bus ( AGP/PCI cards, 
H.D’s, CD-ROMs etc ) is affected.
         

6. Overclocking requirements
============================

The CPU:
+------+

Most CPUs available today are overclockable, and most, to quite a degree. 
Overclocking favorites would have to be the Celeron and Duron due to their 
lost cost and high overcloclability.

The MotherBoard:
+--------------+
The quality of the motheboard in overclocking is highly dependant on your 
success. Due to the fact that the CPU produces fewer 'clean' signals in 
overclocked mode, reflections and other flaws on the bus can cause the 
system to crash or hang. The reverse situation is also true - in overclocked 
mode the CPU is more sensitive to unstable signals from the bus and will 
crash if the motherboard can't deliver clean signals. Always go for a 
branded motherboard! 

The RAM:
+------+
Good quality RAM for Cel/PIII Overclocking is essential, and is very 
important if you're overclocking by raising the multiplier as well as the FSB.


7. Cooling 
==========

	Well there's a lot to be said in this section but first of all we'll 
stick to basics. Whenever you overclock, EVER you should ALWAYS use thermal paste, 
without it your CPU will not live long, due to the poor heat conductivity between 
the CPU and heatsink. The best kind of thermal paste is Artic Silver.

	The most common way to cool a CPU today, even with overclockers is something 
called 'air cooling' which is basically using room temperature air to cool the 
CPU with fans/heatsinks. If you're using  a Peltier or Watercooling, this is 
called 'ACTIVE COOLING'

Fans and Heatsinks - The General rule of thumb with these is: The bigger the better.
You can tell how good a heatsink is ( to a degree ) by looking at the K/W 
value. K/W means degree Kelvin per Watt of power dissipation . K/W tells how 
hot the heat sink gets per each Watt of heating power of the device it's meant 
to cool. If you were able to follow that, you will understand that the smaller 
the value, the better the heat sink.

	Placement of fans is very important, first of all don't fight the air, work 
with it to help you. For Example, put your main exhaust fans at the top of the case, 
as this is where the heat will naturally go.

	It's better to blow air on something rather than to suck air away from it, 
the more air movement there is, the more heat will be moved. And try to keep positive 
case pressure, ie more air being blown in than is being sucked out as this will 
stop any of the air you've just sucked out going back into the case again.


8.Techniques of Overclocking
============================

FSB Overclocking: This option is the ONLY overclocking route available to the 
owners of Celeron and PIII systems, but this does not say that Athlon K6-2/3 
owners can't FSB overclock, but generally Intel's CPUs tend to take to the higher 
FSB better than AMD's does.

Upping the FSB has a dramatic impact on overrall system performance, the RAM 
bandwidth goes up ( Unless you set it to stay at the same speed) H.D Bus speed, 
PCI devices, etc. Not to mention the higher clock rate of the CPU itself. 

	Even if you did have a Celeron that had an adjustable multiplier, you 
wouldn't want to touch it, the celeron is so bottlenecked in this area ( except 
for the new, expensive 100Mhz FSB cels ).


Multiplier Overclocking: This is recommended on all of the Athlons for two ( 2 ) reasons:
* They already have a 200Mhz FSB
* They don't handle FSB overclocking so well

I prefer a mixture of FSB and multiplier raising when overclocking Athlons.


	Voltage adjustment: If you're having trouble attaining a speed, you might 
want to try raising the CPU voltage, just a touch, and see if you get it, but watch 
the temperature because a higher voltage really increases the heat dissipation.


9. Stability
=============

	For your CPU to be classed as 'stable' can be more of an opinion, but in my 
opinion, if you can run Prime95 or SETI@Home for at least 5 days non stop, without 
crashes and while your CPU stays at a comfortable temperature ( Under 50C is good 
that's about 120F I think ) it can be classed as 'stable'


10. Trouble Shooting
====================

	If you get a blank screen on power up or POST ( Power On Self Test )
it means your CPU doesn't like the speed you set it, either lower it or up the voltage.

	There are many other problems that COULD occur, but I am not going to cover 
them in this article.