• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

The AMD overclocking guide

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.


Jan 8, 2002
Boulder CO
The guide below is made for people who would like to learn how to overclock their AMD CPU but have no prior experience in doing so. Enjoy guys!

The basics of overclocking is about getting more out of your cpu investment. It also greatly increases the performance in applications and games and by overclocking you can greatly save time (in applications such as photoshop) or have new features that were previously unabailable to you (like high resolutions in games) available to you.

There are many risks in overclocking your cpu. The main risk is HEAT. However, it is not as big a risk as many beginners believe. Try to keep your temps at LOAD 50C and not higher. However, it is OK if they get to around 55C as long as it is still stable! A misunderstanding with overclocking AMD's is that it will kill your processor in the long run. While this is somewhat true it will not make it unusable throughout the length of its stay in your computer. A CPU running at stock speeds will last 20 years. However, a overclocked CPU may only last around 10 years. Unless you want to keep this computer FOREVER, overclocking is not a risk to your CPU's health at all.

The best thing you can have to battle heat is a great heatsink. Currently as this is being written the best ones available are made by Thermalright, Swiftech, and Alpha. Namely the Thermalright AX7 (or the new SK7) (my personal favorite because of price/performance ratio), Thermalright SLK800, Alpha 8045, and Swiftech MCX462. The best performing heatsinks of the above four go in this order: SLK800, Swiftech MCX462 (however you NEED a big and noisy fan to get this to work right, more on this later), Alpha 8045, and finally AX7 (the alpha and ax7 are basically the same however).

All of the above heatsinks do not come with a fan. Deciding on which fan is right for you is one of the most important things you can do when you decide on how much you want to overclock your cpu. All of the above heatsinks use 80mm fans aswell. The lower the CFM of the fan the lower you will be able to overclock because it will increase the heat of your cpu. You need to decide if you want a dead quiet system (around 20CFM fan), a pretty quiet system (around 30cfm fan), a somewhat noticable but not really system (around 40cfm fan), a noisy but not annoying type of noisy system (around 50cfm fan), or a crazy annoying noise (68cfm or above). Obviously the more cfm you have in your fan the more you will be able to overclock your system because the temps on your cpu will be lower. For amount of mhz overclocked here are the specific types of fans i would recommend:
No overclock at all: Papst 12dba 20cfm fan

Minimal overclock (around 50mhz): Papst 27cfm 19dba Fan

Moderate overclock (around 75-100mhz sometimes more): Sunon 39CFM 32dba Fan

Big overclock (200mhz maybe more)= Mechtronics 53CFM 29dba fan

Huge overclock= Delta 80cfm fan.... sounds like a leaf blower

if you want to hear the fan before you buy it a great place to do so is at http://www.sidewindercomputers.com/tecar.html

now. in overclocking, NOTHING is guarenteed at all. You may get really lucky and have only a 30cfm fan and get a 200mhz+ overclock. or you may use a Delta monster and get only 100mhz+. It all depends on the CPU used as well as the motherboard. Some CPU's are simply duds. I know this from experience because i used to have a SK6 (was the best 60mm heatsink for its time) and a Delt 50cfm 60mm fan on a Athlon 1900+. I could only get a 120mhz overclock with that :-(

a great place to buy the fans is at www.plycon.com

finally make sure you use artic silver 3 thermal grease. I recommend applying the AS3 in a very very thin layer using your finger in a plastic bag. Well how thin? The grease should be translucent and you should be able to partially see the letterings on the core. DO NOT apply a thick coat of AS3 under any circumstances! This will make it melt within a few weeks! If it is too thick it will greatly reduce the cooling potential of it. After you apply the artic silver try to have your computer underload to let it "set in". Letting the AS set in makes your Load temp drop from 2-5C. It generally takes around 72hours for it to completly settle. Sometimes a little less sometimes a little more.

Ok, now that we have the proper cooling out of the way I am going to talk about how to actually go about overclocking the cpu. First you need to know how the stock clock is made. There is the CPU multiplyer and the CPU Front Side Bus speed (FSB). The multiplication of both give you the clock speed. For example. The 1400mhz Thunderbird Athlon is 10.5 mult x 133FSB =1400mhz. Increasing the multiplyer ONLY affects the CPU. Increasing the FSB changes the speed of the whole motherboard and everything connected to it.

As of now, if you want to get into overclocking, it is HIGHLY recommended that you buy a motherboard based on either the Via KT333 chipset or Via KT266a chipset. The KT333 is the same thing as the 266a but it supports faster DDR 2700 memory. An aditionaly benifit of the KT333 is it has a 1/5 divisor which allows for fsb speeds from 166-200mhz to be attainable. The only board out there as of now that has the 1/6 divisor (which kicks in at 200mhz) is the Iwill XP 333 which uses a ALI chipset. However, the bad thing about that motherboard is it is much slower compared the ones based on Via Chipsets. While considering what motherboard you need to consider what you are using your system for and what parts you allready own. If you allready have a RAID card, a ethernet card, and a Sound Card, there is no point in purchasing a motherboard with those integrated onto them. However, if you dont, you can purchase a motherboard with everything (including USB 2.0 and Firewire!) integrated into them. My personal favorite motherboard company is Abit but many others like Asus and Epox as well. I choose Abit because they are rock stable and have EXCELLENT overclocking features.
As of now i recommend these two motherboards depending on the features you want:

Barebones (ie nothing integrated at all): Abit KX7-333 (or "R" if you want integrated raid)
All in one motherboard (has everything integrated into it): Abit AT7

Both of these boards are based on the KT333 chipset. Generally anything from Abit is a great product. However, if those boards are a little to expensive for your budget, i would recommend getting the Epox 8kha+ which is the best KT266a board out there.
Shortly, the Nforce 2 chipset will be available to the public, and in plain words, it will HORRIFICALLY OWN! It will have the one feature that all intel owners have had for a while but amd users have not. The 1:1 pci divisor lock. WTF does that mean? Well it means that you can increase your FSB to ANY speed at all, without having to worry about anything else on your motherboard other than your cpu and ram. If you have fast enough ram, you can even get 250FSB with a unlocked athlon!

By changing the mult or the fsb you get a higher cpu speed. However it is not as simple as just raising both the mult and fsb. First off you need to realize that by raising the FSB you are also affecting every component in your system. The most dangerous thing about overclocking is affecting the harddrive. You want to be careful about the hardrive going above 39mhz because it can get currupted if you do. The default speed of your hardrive, and every other PCI card is 33mhz. Now most of you are probably asking how in the world do i tell how fast the harddrive is running? Well most people who are reading this have either a motherboard based on the via KT266a or KT333 chipset. Both on stock valuses use a 1/4 pci divisor to determine how fast the PCI slots are running. On a stock value of 133mhz, you jus need to divide it by 4 and you will see that it turns out to 33mhz.

For example if you are running the FSB at 150mhz with the 1/4 divisor than you divide 150 by 4 to get the pci cards at 37.5mhz which should be perfectly fine for most devices.

Now that i have explained the BASICS of the FSB i will talk about the multiplyer. Now on amd thunderbirds 1.2ghz-1.4ghz the multiplyer is unlocked by default. however on all Athlon XP processors and durons they are LOCKED and you need to unlock it. it is really not hard at all but it takes a lot of guts and you void your warrenty the second you do it. go check out the sticky in this board on how to unlock or use the search button to find a million threads on it :) The basics of unlocking your multiplyer on locked Thunderbirds/Durons is by taking a sharp #2 pencil and connecting the L1 bridges dots which are found on the surface of the CPU. it should go from this: : : : To this: | | | . On athlon xp processors you need to first fill the pits with a non conductive material (my favorite is with crayon) and then connect it with any conductive grease (my favorite is Rear Window Defogger repair kits)

Ok if you have a Via KT266a chipset that only has the 1/4 divisor, the most effective way of overclocking it is either by raising the cpu mult by .5 (for example the 10.5mult to the 11.0mult) and then raising the fsb as high as you can stabily. Or you can lower the mult by .5 and raise the FSB higher. by lowering the mult and raising the fsb you get higher bandwith. higher bandwith helps you a LOT in games so i recommend doing that over raising the mult and fsb.

now if you have the Via KT333 chipset you are lucky cause you have the 1/5 divisor which kicks in either manually or at 166mhz on most boards. Rather than using 4 to divide you obviously now use 5 to divide the pci mhz. soooo... this means that you can run at 166mhz fsb and still have the PCI cards at 33mhz! With the 1/5 divisor if you run at 180fsb then your pci cards will run at only 36mhz! (180/5). Well now some of you are asking how in the hell will you run the cpu at 180fsb?! that is a lot over the default 133mhz!

you do it by dropping the mult a lot and then raising the fsb a lot. this is very good because it will make your games and apps go a LOT LOT LOT faster because you get a ton more bandwith than was ever meant to be there by amd! (266mhz is the default DDR bandwith of AMD chips and by increasing the speed gives you higher and higher bandwith. As a quick reference point 166mhz FSB is 333mhz DDR and 200mhz FSB is 400 DDR)

For example, with a unlocked cpu you can drop the default mult of a 1400mhz chip from 10.5x to a measly 7x and then up the fsb to 200mhz. however since your pci cards are at 40mhz this can be dangerous to some hardrives (mainly western digitals). Seagates seem to be the best at high fsbs.

Now that i have covered the fsb and mult i will now talk about the hardest thing for a person learning to overclock to understand. the cpu and memory voltage (also called vcore and vdimm). The default vcore on amd athlon cpus is 1.75v. If you keep your voltage at 1.75v you will NOT be able to get that high of a overclock. maybe only 50mhz GENERALLY. If you get a GREAT stepping (discussed later) you will be able to get a very big increase. However, if you raise your vcore to 1.8v, you will be able to get a lot more of a overclock (regardless of what stepping you have)! Now the trouble with raising the vcore is that it increases the heat on your cpu where as raising the fsb does not. That is why it is vital to get a good heatsink/fan combo as mentioned above. I personally use a AX7 and 50cfm sunon and will be watercooling my cpu very soon. Raise your voltage as your cpu gets unstable. For example. If you have a 1900+ AMD Athlon (1.6ghz Clock Speed) then with 1.75v you may only be able to run your computer stabily with the FSB at 138. After you find that out, bump the voltage up to 1.775v and then see how high a fsb you can have. Continue going on until you have either maxed out your cpu or it is getting to hot (over 50c).

The same thing goes for the voltage that you feed your ram. The default vdimm is 2.5v (or 2.55v depending on your mobo). if raising your cpu voltage does nothing to your overclock try raising your mem voltage and there is a high chance that will make it be stable. Now you dont want to kill your ram so in my personal experience the highest SAFE voltage to use on your ram is 2.8v. if you use anything above 2.8v make sure you have a highspeed fan mounted above your ram so it will not get hot.

I know that above is a lot of knowledge to soak in so now i am going to tell you all how I overclock. As i stated above i have a ax7 and 50cfm sunon. I also have very good case flow which was made so by physically modding my case to include a top blow hole and side intake fan. My case temperature never gets above 28C and usually is around 25C. Try to get your case temps as low as possible before you start overclocking because this has a huge affect on how hot your cpu will get. if you dont want to mod it than just clean up your cables for godsakes!

Anyways.... first thing i do is put my cpu voltage at 1.85 v (generally considered the highest "SAFE voltage" with GOOD aircooling (using 40cfm fan or above). I also set my ram to 2.8v.

by doing this i know EXACTLY how high my system will go without anything getting in my way. Next thing i do is i set a end goal for the mhz of my cpu. I currently use a XP 1600+ CPU which is 1400mhz. My end goal for this chip is 1800mhz. That will be a 400mhz overclock. First thing i do is i know how high i want to take my harddrive without risking curruption. For me this is around 38mhz. Since i have a KT333 mobo that means the highest fsb for me will be 190. This will go along perfectly with the 9.5 multi because 9.5x190 is 1805mhz.

So i drop the mult to 9.5 and then set the fsb to something that i am pretty sure will be rock stable, 9.5x170mhz=1610. After doing that i run the burn in program prime 95 (can be found on www.aoafiles.com) for 12hours. What this prog does is it puts your cpu at max load for as ever long as you leave it on. if prime gives you a error, then you need to back it down cause it is unstable.

success! 9.5x170mhz is stable! so after that i raise the fsb by 5mhz again and again until it is unstable. For me it gets unstable at 190mhz which was my goal. So i backed it down and down until i found that the max stable speed for me was 186mhz. 9.5x186=1767mhz. Not too bad for 1.85 v.

Now if you raise your voltage over 1.85 v you need to make sure you watch your temps if you are using air cooling. DO NOT raise your voltage over 1.85v unless you are using a 50cfm fan or higher fan. After raising your voltage up the fsb by 1mhz at a time until your cpu is unstable. then raise it more. however, make SURE that the cpu temps are under 50C while running prime.

On air cooling, if you are using the best cooling possible, a SLK800 and a 80cfm Delta fan (deltas are higher quality than vantec tornados IMHO), the absolute 100% HIGHEST you should put the voltage on is 2.0v. NEVER EVER go higher than that or you WILL FRY your cpu. For the ram it is a general rule not go go above 3.0v

Ok. I just described my aggressive overclocking method. If you want to be more conservitive just dont push your system to its absolute limits. Always experiement with different mults and see what gives you the most speed in applications. For example, if you have a 1400mhz chip you may get higher benchmark scores by running 8x200mhz than you would by running 10x175mhz even though its a 150mhz difference. It all depends on what you use your computer for (if you use it for games than i recommend going and using 8x200).

As for best ram available for overclocking 2100ram generally gets to around 150mhz. 2700ram generally does 180mhz. 3000ram generally does 200mhz. and 3200ram generally does 210mhz.

I use corsair XMS 3200 Cas 2.5 ram and honestly am not as pleased as i should be with it. (i think that Xtreme DDR 3200 is the best ram out there... too bad its $200 for 512mb!)

Now, if you want to see EXACTLY how high your cpu will go under all circumstances, then set your memory timings to the most relaxed ones (the by SPD settings). However, if you are like me, you want to see how high it will go with the MAX AGGRESSIVE settings on your ram first. The max aggressive settings are different on some mobos but generally it is the same. Cas 2.0 4bank then configure 2-5-2-2-1t command. I am sorry i forgot the actual names of the numbers. However, just lower the settings to the lowest numbers and that is always the most aggressive. Well you may ask why i would do this? doesnt it generally give you less mhz? well yes it does. However, if you run your memory at a faster speed but have your cpu 50mhz lower than it can possibly go, it may be faster in many benches still.

The final thing in this mini guide i will talk about are the AMD steppings on the cpu. The stepping are the words on the CPU under the AMD logo. As you see in this pic, the stepping is AGOIA "Y"...

The 0213 after the AGOIA stands for it was made in year 02 and in week 13 of the year. The later the stepping on the cpu the better the overclock.

For athlon XP's the best stepping is AROIA, followed by AGOIA and AGNGA. The best thunderbird stepping is AHYJA i think i have never used one of those processors. GENERALLY if the second line starts with a Y or K it is a great overclocker. If it starts with a 9 or a 4 it is a good overclocker and possibly a great one. if it is a Z then RMA the cpu ASAP cause it will not overclock at all. One of the worst athlon XP stepping is AGKGA.

I think that about covers the amd overclocking guide. Feel free to post questions or PM me if you would like. Any veterans to these forums also feel free to add anything that I may have missed by accidnet.

Have fun guys! Make sure you post your overclocking results on this forum! I would love to see them!
Last edited:
No offence, but before a heatsink, thermal paste or even a chip the motherboard is the heart of an overclocking system. Without a motherboard you can't do nothing, no options no overclock.

The guide looks good.


See below for some clarification.
Last edited:
james.miller said:
lol i suppose Emericana was asuming people already had a working system

Let me rephrase that, a good motherboard. Quality is what you're looking for not just a working motherboard.
Yeah sorry about the confusion i was assuming you allready had a working computer. As for motherboards, right now the KT333 is the best chipset you can buy (my personal favorite being the Abit KX7-333) but if you want to save some money the KT266a is definetly a option. The best KT266a board is the epox 8kha+
ok. I'm trying this for the very first time, on my brothers computer. It is an amd 800mhz. The board is a gigabyte but the only switches on the board are for the fsb.. The highest I could get it to was 112 so now my processor is running at 896 just fine, is this all I can do with this board and proc? I tried going to 133 which would have gotten me up to 1064 m
so the multiplier is set at 8 obvisouly, 100 was the default fsb. that's pretty much what I understand. Is there anything else I can do to up it? There isn' even a switch to up the vcore.


:D My first oc was a success!!! kodak moment

Any more help would be great
I can feel a 4x cmmin on, sorry a sticky that is, (if you live in au you will undertand the 4x bit, t is a beer ad.

but seriously good work, should keep newbies happy and as for my mobo am going 2 nforce2 or if I can hold out hammer system!
Nice :)
However before it can be considered for a sticky I'd like you two make a few changes :)

They are minor but when done it will truly deserve more recognition.
They are minor but you left a few things out, one like Yodums said is the Motherboard which is the most important part of an overclocking system (or any system for that matter), also (not sure if you put this in I skimmed through it, I got a stack of emails to answer :rolleyes: ) randomization, meaning every part overclocks differently and behaves differently (I won't go into detail).

Also its not 100% user friendly, it does get a bit confusing, simply bad word positioning, just read through it then you can easily re-position it and make it a whole lot easier to read (grouping, punctuation, highlighting key area's etc).

I'm not at all means criticising your efforts, I'm simply helping you release this guides full-potential, please take it as a positive contribution :)

Good Work,
Make the changes and a sticky may well be in the cards ;)
Ok I just wrote this, its by no means finished and (by my standards is rather rubbish :p) but it should give you an idea of a few of the things you missed out,

You will need to unlock your CPU first, do this by joining the L1 bridges with an HB pencil, but DO NOT short the bridges, this could cause permanent damage to the chip and board.


Use a Sharp pencil, Magnifying glass, Lamp, if it goes wrong simply rub the pencil out!

See the highlighting effects?

Now that you've done this raise the Multiplier (leave the FSB > (front side bus) for now) do this, (small increments) run 3DMark or a CPU burn-in program. If its stable then Overclock a bit more.
Once you get unstable, up the voltage until its stable. Then raise the multiplier some more.
Make sure you watch the temps whilst you do this. (50C) is to hot and can cause instability.
Remeber that oc'ing needs good cooling, else it will crash and cause errors. You can overclock more stably at lower temps!!!

Now you have found your highest CPU speed, lower the Multiplier and RAISE the FSB instead. This will increase the speed of EVERY component in the system. You will benfit from increased speed thus, (don't worry about the heat, none extra is produced) but this causes instability in most cases when you go over 170FSB due to components such as the sound card being well out of spec.

If you have memory Voltage Adjustment you will need to raise it to get over 150FSB with most memory as again it will be out of spec. (DDR overclocks better in most cases)

Basically you need to find a stable optimum of them both!!!

Hope this helps! PM me with any other problems/advice you need help with.
You might want to take a look at my Sticky in the Vid/Sound cards section to increase your PC's overall speed. (via Tweaking)

Just remember two rules:
1. Every system is unique, in oc'ability, stability, and heat.
2. Watch your temps!

Happy Overclocking!!!

Just take a look at my Guides for a rough basis, (I was going to write my own Overclocking Definitive Guide, discussions are happening ;) )

Last edited:
Emericana said:
Ok guys I haver personally gotten tired...

... this means in dumb terms...

... make your games and apps go a LOT LOT LOT faster...

Now that i have covered the fsb and mult i will now talk about the hardest thing for a newbie to understand...

Well we should be all so happy that you took the time to write up a guide for "NEWBIES" like myself. Like most of us here who are always learning something new everyday I like it when somebody takes your tone to teach the beginners the facts of overclocking.

Be more sensitive to the begginers & not just lead them to water so they can drown.
Another suggestion from the peanut gallery

Nice guide bro, I vote to sticky this as well.

Just one more edit I would suggest... the part where you said "1.75 Volts will not get you a good overclock... switch it to 1.8" -- this is generally true, but I would say "most likely not get much of an OC" instead of just saying you won't.

I say this because with all the AGOIA and AROIA chips it seems like people CAN get a good OC at stock voltage. Mine for example will do 1766 (366 MHz OC) Prime stable at default voltage.
4 Things I'd like to add:

Disable spread spectrum

Make sure RAM is running in syncronous mode (HCLK/133/266 setting, depending on the mobo...probably lots of other variations)

Make sure RAM timings are relaxed

Did you mention CMOS clearing and what to do when your comp freezes and what not?? How to recover from a corrupted config file...etc...

Adding those would allow people to avoid some headaches...

Otherwise, very nice job though!!!:beer:
garasaki said:
Make sure RAM timings are relaxed

i would rather say that you should try to relax the mem timing IF your overclock is unstable. if it is stable then keep them on the most aggressive you can as this adds to the performance of the pc.

its getting better allready. come on, STICKY it!:)
Well, I meant start with memory timings relaxed, then find your max OC, then start tweaking them....Guess I should have been more clear