# Fantasies of Overclocking - OC guide



## quad master (Dec 8, 2005)

*Fantasies of Overclocking
Taking your Computer to a New Height*

Before we start on this journey some people might have some questions at the back of there mind.

Let us clear them first.

*What is overclocking ?*
There is no specific defination for overclocking as such. Overclocking is an 
art of tweaking your hardware settings in the Motherboard BIOS to extract 
more juice from you CPU & Ram. "More Juice" mean more CPU & Ram 
Speeds. Most of the people all over the world do overclocking as they 
really enjoy it. In India its not much popular but there are people 
scattered around India which take overclocking seriously. Overclocking 
also requires special cooling hardware like Air Cooling or Water cooling for 
Normal Overclocks. Liquid Nitrogen for Extreme Overclocks.Normal 
Overclocks means increase in speeds from 500 to 1000 Mhz & Extreme 
Overclocks means Record breakingcompetions here speeds increases 
from 2Ghz to 3Ghz extra over stock speed.


*Why do we overclock ?*
This is a very strange question to answer. Overclocking is done to enjoy 
the benefits of higher clocked processors & rams from lower clocked ones. 

For  Eg.  A Intel P4 3.4 Ghz will cost more than a Intel P4 2.8Ghz. But with 
the help of Overclocking you can increase the speed of a 2.8Ghz to a 3.4Ghz and save money.  


*Disclamer:- Overclocking can possibly damage your hardware when not done with care.. Sometimes even when care is taken things can get damaged since you are pushing things past the limits they were intended to run. So I am not at responsible for any sort of damages caused.

Note:- Most of this article is written my me but some part is also taken from the net. *

Lets start . . . . 

Overclocking can be done for both Intel aswell as AMD based systems but you get more flexibility with AMD , How you will understand
as i proceed. 

*The Basics *
To understand how to overclock your system, you must first understand how your system works. The most common component to overclock is your processor. 

When you buy a processor, or CPU, you will see its operating speed. For instance, a Pentium 4 3.0GHz CPU runs at 3.0GHz, or 3000 MHz. This is a measurement of how many clock cycles the processor goes through in one second. A clock cycle is a period of time in which a processor can carry out a given amount of instructions. So, logically, the more clock cycles a processor can execute in one second, the faster it can process information and the faster your system will run. One MHz is one million clock cycles per second, so a 3.0GHz processor can go through 3,000,000,000, or 3 billion clock cycles in every second. Pretty amazing, right? 

The goal of overclocking is to raise the GHz rating of your processor so that it can go through more clock cycles every second. The formula for the speed of your processor if this: 

FSB (in MHz) x Multiplier=Speed in MHz.

Eg  200 x 15 = 3000Mhz 

*What is this FSB and Multiplier ?*
Here in the above example 200 is the FSB [or HTT HyperTransport incase of AMD] and 15 is the CPU Multiplier. For most of the current
system the stock or default FSB speed is 200 and whatever other components that are running in the system are based on this FSB speed.
So if you increase you FSB Speed [200 here] you can increase the clock speed of you CPU & Ram. Also in Intel based processors the CPU
Multipler is locked i.e. it cannot be changed but in case of AMD there are 2 types of processors AMD Athlon 64 & Athlon 64 FX Series
in the normal series the CPU multiplier can be lowered but in FX it can be lowered as well as moved upward , that  is the reson why i told
earlier that AMD is more flexible.

Further explaination will be only with respect to AMD based system it will be the same for Intel based only in Intel the Multiplier is locked.

This is how FSB or HTT Speed determines various values.
CPU Speed:-  200 x 10 = 2000 Mhz.
FSB Speed:-  200 x 4 = 800 for Intel & HTT Speed for AMD 200 x 5 = 1000Mhz [1000 x 2 = 2000 actually]
Ram Speed [DDR]:- 200 x 2 = 400Mhz  [ for DDR 400 Ram ]

Note: For AMD even the 5 which is the HTT Multiplier can be changed.
When overclocking you want to lower this setting to maintain stability. On a socket 754 its best to keep your total HTT speed around 1600htt or less, this will not effect performance if running under spec a little.. On socket 939 its best to keep it around 2000htt.. Sometimes on 939 you can even get away with overclocking the HTT buss a little but honestly Ive never seen a performance boost by doing this..

Now that you have understood how basically everything funtions lets look at how we can actually increase the speed to extract a few 
Mhz from your system.

All the overclocking that has to be done will be done throught BIOS Advanced settings section.

*Various Parameters*

HTT Speed: 200 x 5 = 1000
HTT Multiplier: 5 / 4 / 3 should be adjusted such that HTT Speed doesnt increase over 1000

*CPU *
VCore:- Voltage fed into CPU ,  should be increased when the speed is increased to increase stability at higher speed.
CPU Multiplier:- Lowered only if required

*Ram*
Vdimm:- Voltage fed to DDR Ram varies for different Ram Chips

*Before you start Overclocking *
- Lock your PCI/AGP in the bios by setting it to  33/66. With an MSI board, go ahead and set the AGP to 67 to activate the lock.
- Disable Cool n Quiet Technology for AMD Only.

*Step #1: Find out how fast your memory can go*

In order to find this, you will have to slow down your CPU, so we are completely sure your CPU isn't what's causing any problems. To do this, drop your CPU Multiplier down 2 spots from wherever it is stock. Some might argue you only need to drop your multiplier down one spot, which will more than likely work just as well, but 2 spots assures the CPU is not being pushed too far. Also, if you can set your PCI/AGP in the bios, set 33/66, respectively. With an MSI board, go ahead and set the AGP to 67 to activate the lock. Find your HTT multiplier (should have options from 2x up to 5x (socket 754 only has up to 4x max I believe)), and make sure it's at 4x. Also, disable Cool 'N Quiet if it's enabled....for some reason, it causes strange abnormalities when overclocking. Keep the FSB in the bios @ 200MHz and boot into windows. Go on increasing your HTT from 200 in intervals of 5MHz.

Download Memtestx86 to testRam stability when its overclocked and create a bootable cd of it.

Take the last memory speed before it crashed (say it crashed at 230MHz, but ran fine at 225MHz ) and set that number (or a little lower if you're unsure) into your BIOS for HTT. Now, reboot and insert either the CD or floppy and memtest should boot. Let it run one pass (all tests, takes about 20 mins or so for one pass), and see if you get any errors. Errors would be BIG UGLY RED LINES across the bottom. If you get any, or it locks up for any reason, reboot, and lower your FSB in the bios by one or two MHz. If you get through the first pass with no errors, feel free to add 1 MHz incriments and repeat the test until you find errors or issues like lockups. You have officially found the ceiling of your memory when you have no errors.

*Step #2:Find out how fast your processor can go*

Now comes the fun part. Reboot back into the bios, set your CPU Multilplier back up to where it should be, and put your FSB at 205FSB. Reboot, and see if everything works fine (gaming is a great way to find this out). If after about 20 mins it's completely stable, go for it again, adding more FSB (try 5MHz at a time) until you get a Blue Screen Of Death on windows load, it locks up, or you reach the ceiling of your memory. Check your motherboard on how to clear your BIOS settings so you can boot your computer back up (usually a jumper you have to move) in the event your computer refuses to start. Also, keep a close eye on your CPU temps. Don't let your load temps go over 50C. If they do, drop your MHz in the FSB down until it goes lower. Once you find a speed that doesn't exceed 50C in temp under load , reboot your computer back to memtest, and let it run overnight. If you have no errors, then you're done! Also remember, load your graphics card while trying to find your temps. I recommend 'rthdribl' to load graphics card (google it). Your videocard warms up, and therefore your case warms up, so therefore once again, your CPU temps go up higher. Just remember, the lower the CPU is rated at (3000+ versus 3500+), the more headroom it has for overclocking (as in you can ADD more MHz, not get more....the 3200+ runs @ 2.0GHz stock, while the 3500+ runs 2.2GHz...they both can probably hit 2.4GHz no problem, but that's 400MHz headroom on the 3200+ and only 200MHz on the 3500+, see the difference?). Also remember, overclocking is different for EACH piece of hardware, so NO RESULTS ARE GUARENTEED.

*Memory Timings *

TCCD is one type of  Chip used for the Ram and are very costly , here maximum of the people get Hynix D43 Chips for the standard ram which we buy in market as Transcend or Hynix Ram.

This is mainly for those of you who bought this magical "TCCD" Memory that overclocks really well. Perhaps you've tried overclocking it before to less than ideal overclocks . The thing with TCCD is, it SPD's to 200MHz @ 2-2-2-5. Confused yet? Hold on, I'm going to try and explain. SPD is what the company who made your memory (Corsair, Kingston, OCZ, etc.) says it should run at running default speed. TCCD chips are fast, so they can run the lowest timings Athlon 64's chipsets let you specifiy, which is 2-2-2-5 (more on those numbers in a second). Now, each of those numbers stands for clock cycles (like same clock's your adding to in order to OVERclock, which make up your GHz on your CPU). Basically, you can't just reach into the memory whenever you want, you have to wait until it's ready for you, and that's where timings come into play. Now, the lower the numbers, the more demanding you are on the memory, so you lose the ability to overclock. The timings USUALLY stand for CAS-CAS to RAS-RAS-tRAS (sometimes there's in a different order, but the biggest number is always tRAS, while the lowest is always CAS). Now, I've read and understand what they mean, but trust me, it's REALLY confusing. Just get used to their names, since you'll hear people talking about them....read into them if you're curious.

So now you realise (or I hope anyway) that TCCD doesn't come out of the box, ready to overclock. Now you need to loosen the timings...but all those #'s, all those possibilities to change stuff, how's one to choose?!?!? I'll try to help. Here's the order I PERSONALLY have come up with that, once you bring the # up, has the most impact on bringing up your overclock, assuming the order is CAS-CAS to RAS-RAS-tRAS

4-2-3-1

Where #1 is the first you'd loosen up, then #2, then #3, then #4, and you may have to loosen say 2 and 3 2x before you loosen #4 once. Confusing yes, so I'll give you a cheat-sheet that works for my memory, and should work for most TCCD.

PC3200 (400MHz) 2-2-2-5-1T 2.6-2.7v 
PC3500 (436MHz) 2-3-3-6-1T 2.6-2.7v 
PC3700 (466MHz) 2-3-3-6-1T 2.7-2.8v 
PC4000 (500MHz) 2.5-3-3-7-1T 2.75-2.85v 
PC4200 (533MHz) 3-4-4-8-1T 2.85-2.95v 

All these 400 , 436 , 466 are your overclocked ram speeds only if you have a TCCD based ram with Hynix D43 Chips you can reach
max of 230 to 240 x 2 = 460 to 480 Mhz speed that also if you get orignal Ram as there are a lot of fake ones available in the market.

I recommend for a first-time overclocker, to go with the 2nd to last one, 2.5-3-3-7. To change these timings, go under DRAM settings in your BIOS wherever that is Alot of people will tell you to give memory more voltage to help overclocks with TCCD and non-TCCD. TCCD memory personally gets less stable with more power, and seems very happy @ 2.7v, including 500MHz where it says I should have at least 2.75v. 

*Memory Dividers*

Sometimes, when on a budget, you get memory [common in India] that can't exactly overclock the best. In this event, you can set a divider so the memory runs slower than the FSB you set. You can tell the CPU you're running the FSB as 240MHz, but your memory only runs at 200MHz. In order to set a divider, go into your BIOS, and you can specify for memory's speed. The options should be:

100MHz [1:2]
133MHz [2:3]
166MHz [5:6]
200MHz [1:1]
Auto

You may not always see 100MHz, but at least the other 4 should be there. By default, it'll more than likely be on Auto. Now you may be thinking "Wait a minute, my memory is 400MHz!" Well these are the actual clocks of your memory, and since it's DDR (Double Data Rate) It's 2x the speed listed here, a.k.a. 200MHz. By default, it should be set at Auto. Don't worry about the 200MHz settings, auto does that by itself. You'll be using 100, 133, and 166 for dividers. The dividers give you the following results...

100MHz = 1:2 (memory runs 1/2 the speed you set the FSB as, so 200Mhz FSB = 100 MHz memory)
133MHz = 2:3 (memory runs 2/3rd the speed you set the FSB as, so 200MHz FSB = 133 MHz memory)
166MHz = 5:6 (memory runs 5/6th the speed you set the FSB as, so 200MHz FSB = 166 MHz memory)

So, if your memory's ceiling is limiting your overclock, and you can use a divider to get the CPU running faster...the only problem is, this doesn't always give better performance, because the CPU can't access the memory at all times, so sometimes it has to wait on the memory. The speeds I listed with the dividers are NOT the speeds you have to or should run, they just show you how high you have to go to reach the memory's stock setting. You can use any FSB with any divider...but use the smallest divider possible if you must use one (like 5:6). Also, you can loosen memory timings to enhance your memory's ceiling.

*Check Overclock Stabability*

Now you (hopefully) have an overclock that runs inside Windows no problem. Well, because it runs in windows, that means everything is working correctly, right? WRONG. Windows allows for errors (games too) without crashing, but remember that your CPU is just a big calculator, and with wrong math coming out, alot of the stuff you do will come out borked. Stuff like Folding will give inaccurate results, and not help anyone. Also, encoding things will give strange results. 

- Install and run Prime95. 
- Click 'Options', then 'Torture Test...'. 
- Click the button that says Small FFT's (checks ur CPU only, since that's what you overclocked and memtest checks 
ur memory anyway).Press start, and pray , 
- If you get an error mentioning rounding to .5 or .4 and should have been the other, than your memory is "probably" too high, 
and you need to slow it down. 
- If you get a message that's like "was expecting 89248932480932480324 but got 8329483284290348093248" 
(NOTE THOSE ARE NOT REAL Numbers , JUST MADE THEM UP ), then your CPU "probably" needs more voltage. 

Note that adding more voltage on stock cooling is not recommend personally. Adding voltage brings ur tempature up noticeably, even if you are still running the same MHz on ur CPU. For a beginner, I recommend just lowering your overclock until you get no errors for 12 Hours of Prime95 (just set it before you go to sleep).

*Adjusting Voltages*

Note: Extra Voltage on stock Cooling is not at all recommemded

When you run your CPU past spec, it requires more power to do the job you tell it. You can adjust voltages in Windows using a 3rd party program like Clockgen or MSI CoreCenter or ASUS AiBooster or in the BIOS[Best]. The main thing to keep in mind is, adding voltages substancially brings up your CPU's temp. Now, say you've found an overclock that runs in Windows, but won't Prime....this is where voltage will (more than likely) fix the problem. Try bumping the CPU .05v up from the stock voltage, and try running Prime95's Small FFT test again. Fail again? Try another .05v. As long as your CPU stays below 60C you should be alright...also, I wouldn't recommend going .1v over stock voltage on stock cooling (mainly for winnie users since they run cooler and use less voltage) if you're really feeling lucky. On water-cooling, or really good air cooling, .25v is the absolute highest I'd go. Also, some memory likes higher voltages to get better overclocks....some becomes less stable. This is more of a "trial and error" kind of thing, and I personally don't see any problems with running memory @ 2.85v, most memory you'll have will SPD @ 2.6v, maybe 2.7...try a .1v bump and see if it helps. If not, it's pretty likely no matter what else you try you probably won't get any better results, voltage wise.

There is still a lot to be explored but its beyond the scope of this article.

Hope this answeres all the questions that most of the people who have just started overclocking.

Happy and Safe Overclocking.

*Mods if u feel this article is really worth it please Sticky it.*


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## abhijit_reddevil (Dec 8, 2005)

Great post, boss, it will surely help overclocking novices like me who like to experiment.


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## vijay_7287 (Dec 8, 2005)

good one dude !!!


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## cryptid (Dec 8, 2005)

how do we unlock the multipiler for Intel Pentium 3 and 4 
processors


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## Ringwraith (Dec 8, 2005)

every hardware forum worth its salt should have a sticky for o/cing


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## mangemayur (Dec 8, 2005)

great job man, will try to do overclock today ..


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## quad master (Dec 8, 2005)

*Mods if u feel this article is really worth it please Sticky it.*

This article will answer most of the common overclocking related doubts.

@cryptid - Multipliers cannot be unlocked its upto the chip manufacturer to keep the multipliers locked or unlocked.

Intel is CPU multiplier is locked and connot be changed.

Intel Extreme Edt. mostly has it unlocked [not sure on this]

AMD has its processors multiplier unlocked on the FX Series of processors that means you can increase it as well as decrease it.

AMD's Athlon XXXX+ series has its multiplier movable downwards but u cant move it up.

Thats why i feel AMD is really gr8 as we have the flexibility with the CPU multiplier but with Intel its locked up and down.

The CPU Chips with unlocked multiplier cost a bomb.


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## yogi7272 (Dec 8, 2005)

All Intel  Pentium 4 Extreme Edition and Pentium Extreme Edition processors have unlocked multiplier .. maybe that's why they are soooooo
costly ...   

Also Pentium 4 - 600 series processor's multiplier can be lowered  upto 14 ..  
but it is locked upwards..


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## dIgItaL_BrAt (Dec 8, 2005)

thanx for the info,dude!


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## ashnik (Dec 8, 2005)

2 words


wholesome info


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## Aniruddh (Dec 9, 2005)

ooh man thats a gr8 info.ofcourse this will help loads of people who wants to overclock but cant as they dont kno much bout it.i feel this shud b sticky.


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## quad master (Dec 9, 2005)

Guys i would like to tell you that this was my first article which got published in my college news letter.

Thanks for appreciating my efforts.


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## quad master (Dec 14, 2005)

----> BUMP <-----


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## hsksattish (Dec 14, 2005)

Hey I just want to know the exact temperatures of my cpu before overclocking.But I dont know how.
In many places i have read that the BIOS is often wrong in reading temperatures and I found it so-In my bios usually temperatures are around 70degrees 
and when i used speedfan they are about 44 degrees.Which one is correct?


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## quad master (Dec 15, 2005)

BIOS is mostly correct.

If u are using Intel Presshot[Prescot] Core CPU's
on a Stock cooler the temprature does reach that 
high.

If u are using a AMD Athlon Winchester or Venice Core then ur temprature will remaing in the
35 to 50 Range.


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