Picture of How to overclock Intel CPUs?
First of all let me make it clear that overclocking basically means to over-work your hardware and make it operate beyond what it was designed to do. This can sometimes result in permanent damage to your hardware. But don't be afraid, if you carefully follow these instructions, be patient and calm, overclocking will become second nature and you won't end up damaging anything. Trust me!

Let me also make it clear that there can be no definitive step-by-step guide to overclocking in this world, each individual component has different limits and each motherboard has different options and BIOS versions, meaning that OCing (I'll refer to overclocking as OCing from now on) is more of an art then it is a science. This instructable is strictly for Intel CPUs, AMD OCing is drastically different.
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Step 1: Requirements and considerations

Picture of Requirements and considerations
First of all, I would like to mention that OCing of Intel CPUs can be done in two main fundamental ways:
1) Increasing the Front Side Bus (FSB), which means to increase the data transfer rate between the CPU and RAM
2) Increasing the multiplier, this option isn't available to most users since almost all Intel CPUs apart for the Pentium Extreme Edition and Core 2 Extreme have their multipliers locked.

Another thing is that we would be using the BIOS to perform all our tweaks, there are various softwares out there, but they only support a limited number of motherboards and are not that reliable. Also note that when you OC CPUs, you are also OCing your motherboard (in which the FSB is implanted) and your RAM. OCing RAM is notoriously tough and risky, but you can deal with this issue by decreasing the FSB:DRAM ratio we will be discussing later.

Ideally, you'd want these motherboards to OC on:
Intel P35
Intel X35
Intel P45

These motherboards are not so good at OCing:
Intel 946 chipset (though I personally have it and managed a 25% OC without any problems)

Perhaps the biggest problem with OCing any component is overheating. If you want really high OCing capacity of 70%+ then nothing other then a water or liquid cooling system will do. mid-range to high-end air cooling is known to be able to OC to around 60% while stock cooling can only reach 30% at max (my E2160 has stock cooling and a 25% OC). There is no exact temperature limit for any CPU. But as a general rule, you wouldn't want your temperature at any more then 75 (degrees celsius) under load. Having it at above 60 degrees shortens the lifespan but that shouldn't be a worry if you don't plan on using your CPU for more then 2 years.

Recommended software
To check for basic statistics regarding your CPU, I strongly suggest that you download the CPU-Z utility from:

And get Speedfan for closely monitoring your temperatures, but before this, look around the CDs your motherboard came with for a specific utility for monitoring them. ASUS motherboards for example, come with ASUS PC-Probe which is far more accurate then universal monitors. But here's the download link if you don't have one:

Also, download a simple application called SuperPI, which essentially gives your CPU a task to do and times how long it takes for the task's completion. Note that this application doesn't support multi-threading meaning it can only utilize the power of one core even if you have 2 or 4 But the purpose here is to check for basic stability and performance increase. You can get it form here:

Step 2: Entering the BIOS

Picture of Entering the BIOS
Now then, its time to get down to some actual OCing. Enter your BIOS and navigate to something like "Advanced Settings", if you have an ASUS motherboard, then I can tell you to straightaway enter the "Jumper-Free configuration" in the "Advanced" tab. Regardless, in all motherboards, all the OCing options are located in one place. For details as to where these options are, refer to your motherboard's manual or download it online.
I recommend that before proceeding, you disable C1E support. For ASUS motherboards, it can be found in the "CPU Configuration", its optional though, I haven't done it.

Step 3: Changing the values

Ok then! Lets get OCing. First of all, you want to increase your bus speed which is at 100MHz - 400MHz. Note that this value, multiplied with the multiplier, equals your final CPU clock speed in MHz. So in the case of my dual-core E2160, the default bus speed (200) multiplied by the multiplier (9x) equals 1800MHz or 1.8 GHz. So, get down to increasing the bus speed, make only minor increments at once, don't get over-confident or impatient, this is what results in accidents. Increase the value by 5 at maximum at one time. Then save changes and exit the BIOS. Next, see if your Windows boots or not, if it fails to boot or restarts automatically during or after the boot process, it means you've gone too far. Re-enter the BIOS and step the CPU back down.
If it goes strong however, do some benchmarking of your system using something like SuperPI, and to be 100% sure, run some games for a while. If it remains stable, head beck into the BIOS and step the CPU up again, repeat this process until your you experience instability.

Step 4: The CPU won't overclock any further!! What to do??

Picture of The CPU won't overclock any further!! What to do??
Sooner or later, you'll hit a point where the CPU just can't take it anymore and you will start experiencing instability. But don't be depressed just yet, there is a way around:

1) the most common way is to increase the CPU vcore voltage. Make only 0.05 - 0.1 volts increments at once, anymore could permanently damage your CPU. This is a very common tactic since an OCed CPU needs more watts and volts to handle the extra tasks at hand. Also note that "AUTO" settings aren't at all good ionce, even at stock, they supply too much or too little voltage. Also don't increase your voltage too much, anything above 1.4v for a Core 2 chip is not recommended since it increases electronic migration and drastically decreases your CPU's life.

2) Before you increases the voltage however, I recommend that you step down your RAM timings as well. Check your specific RAM model number for its details specifications. If you find that it has something like PC2-5300 on it or 667 MHz, then it means your RAM operates at 667 MHz. If it has PC2-6400 said or 800 MHz, then it means your RAM operates at 800 MHz. If you have PC2-4200 or 533 MHz said, it means your RAM operates at 533 MHz. In cases of expensive RAM, you may have 1066 or even 1200 MHz RAM, which is, in effect, factory OCed RAM that is stable. Check CPU-Z for your RAM frequency. Make sure your RAM isn't OCed by anymore then 15% because this isn't very good for your RAM's life and health. Decrease your RAM's frequency by 133 MHz (which will be the default option i.e. you will be allowed to choose from 533, 667, 800 depending on the maximum frequency your RAM can handle). By doing so, your FSB:DRAM ratio automatically drops or it may be possibe that you have a direct option to change this ratio

In some motherboard BIOS, you might be able to enter a specific number manually which is even better. Once you decrease the RAM frequency, your OC will only add to that decreased number, which means, that in the end, your RAM will be operating somewhere close to its desired speed. The RAM's frequency will be mentioned as DRAM frequency in your BIOS. However, if you have 553 MHz (or PC2-4200) RAM, then you might not be able to select any lower option since this is the slowest speed at which DDR2 RAM operates.

Note: Theses specific numbers (i.e. 533, 667 and 800 are unique to DDR2 RAM. For other RAM types such as DDR, SDRAM the values will be lower while for DDR3, they will be significantly higher

3) Just be happy with what you have and quit OCing! (not the desired option for a brave person)

Step 5: Future advice and troubleshooting

No then, if you have been successful, you'll be happy to get some extra performance at no extra cost. But do note that, some time in the future, you may experience instability which may make a late appearance as your CPU ages. In such cases, down-clock your CPU just enough to make it stable.

You might find my guide missing some information, this is because I have tried to make it short unlike all the other guides on the Internet which are of 10 pages! I've shortened it to the best of my capabilities and have missed out on a number of things. If you have a query, then please feel free to ask any questions through comments.

As I said before, it isn't possible to make a complete how-to guide for OCing since it differs from case to case but, again, feel free to ask! And remember, (I don't want to sound like an Intel fanboy but I'm forced to say this) I can only help you with Intel processors. AMD overdrive and HyperTransport works in a completely different way, but you can still ask and hope for someone else to answer.

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Muscelz6 years ago
very nice instructable :) im running my Pentium D 945 which is stock at 3.4ghz @ 3.65ghz--(idle 34oC, full load 45oC. using the Cool Master V8 heatsink), very stable obviously becuase of such of a minor OC. i decided to put my cpu to the limits. i hit 4.4ghz (idle 40oC, full load 60oC) and had had trouble doing most things without getting a blue screen :S i had to set my core voltage to .1V over its stock rating which alowed me to gain stability. which i DID NOT like doing. but it waz only for a short time damnit it wont let my add a pic. uhm... if u wanna see add me on msn bloodhound73@gmail.com
Muscelz Muscelz6 years ago
the pics
4.4ghz overclock.bmp04-04-09_2105.jpg
Wow, 4GHz!
only a 600mhz OC, isn't to great. but its pretty good for me
Well 600Mhz Overclock seems pretty good for a first timer, was it your first time doing this?
ive been overclocking for a few years now, that wasn't my 1st. i was just seeing how high i could get my 945 up to till i was causing damage
Oh...XD i got a 500 MHz Overclock on my first time ;) i think its pretty good :)
the Pentium D failed on my a few days ago, it lost stability on stock freq, so im using my spare Dual Core E1400 till i build my new rig, its clocked to 2.66ghz, thats 662mhz above stock freq. no voltage changes, still stable as
Stable as what?
stable at its stock frequency and that was 3.4ghz. my dual core is out performing it now lol
It was probably overheating, Was it a laptop or desktop?
no, it wasn't overheating. it wasn't going over 35oC on full load, its a desktop and and its got a massive Coolermaster V8 Heatsink on it. so definitely not over heating
Well i don't know, it was perhaps a defective processor.
yea, im going I7 now. my new build will cost me 6grand lol
6 Grand? You might as well buy a mac, a pc does not get that expensive while being worth it what are the new pc's specs?
rofl, not a mac, I despise them. here's the specs, I'm ordering the parts next month, i shud have the money by then

EVGA X58 Classified E760 Motherboard
Intel Core i7 950
Corsair TR3X6G2000C8GTF 6GB (3x2GB) DDR3 (x2=12gig)
EVGA GeForce GTX 295 CO-OP Edition (x2 for SLI)
Corsair P256 SSD(256gb) (For Games and OS)
Western Digital RE3 1TB WD1002FBYS (Media etc)
Corsair HX-1000W 1000W Power Supply
Lian Li TYR PC-X500
Xigmatek Thors Hammer Double Layer HDT CPU Cooler (CPU H.S.)
Corsair Dominator Airflow 2 Fans (RAM FAN)
Lian Li TYR PC-X500 (CASE)

My idea is to get good quality gear so you won't be replacing faulty parts and it will last

so around 6grandish $AU

Hey Muscelz, instead of a i7 950, try the new Haswell i7 4770K

Muscelz Muscelz6 years ago
and i got a pre-order for Windows 7 x64 :D she's gona fly
Nice windows 7, Pre ordered, I would if i had money, the prices are pretty good now, but they are gonna go up :( Sky high I would be a little careful about Installing vista's brother 64BIT , though 7 is better than vista in many levels Especially being fresh out of the oven...Ahem...Microsoft you remember how the first vista beta was? and 64 bit...
lol yea, as buggy as hell. but that dnt phase me, i got XP PRO x64 and Vista Ultimate x64 as back up oh and Debian. the serial for Win 7 is all i want
XP 64 bit? Debian? Vista? How big is Your HDD?
i got close to 2tb of storage
-max- Muscelz3 years ago
i can see you having a supercomputer soon and have the ability to download the internet to you computer!
Wow, Pretty sweet i got an itty bitty 80GB -_-
 =[ whats wrong with mac, u could get an 8 core mac pro or wait until intel releases it i9 
Wow, I heard that some extreme processors from intel are costing up to 1000$! WOW!
lol yea, myne cost me 1.3grand, i got a 975 atm
Lol, I overclocked my computer to 4.8 GHZ. It was 3.0 ghz. It did not get hot, or malfunction. But still I stopped it because i did not want my computer to die.
If it does not overheat it will not kill your computer XD Was it stable? I noticed that when my CPU nears 170 Degrees My OS starts going unstable, At about 150 it sets the fans to high speed, and cools down again. I remember on an oldie laptop, the CPU will tolerate temperatures up to 200 Degrees! 190 Degrees is the standard temperature XD It has a passive heatsink...
they can tolerate that for a very short time, running @ 100oC for a cpu is like taking 1000 hours off the cpu's life. its ensentially wearing them out, think as it as redlining your car 500rpm over "redline starts" for a small OC, there for just a small jump over redline means increased heat, meaning will tend to wear more therefore taking hours off the engine and in this case hours off the cpu if you can understand it that way
Well...No...if the overclock doesn't overheat the CPU, it would last as long as any CPU would last(pretty much forever)
yes, some overclocks don't make components over heat, what im trying to say is its being flogged, they are only designed and tested to run at a persific frequency because they will have longer life etc etc, its the component internal strength will be diminished over time, and once over clocked, the cpu WILL lose expected life FULL STOP overclocking increases the break down of the structural integrity of a cpu/component
By the tiniest bit.
lol no, some cpu's 100mhz over stock freq can 1/2 its expected life, they are made to a degree where they reach "WEAR POINT" where the cpu will dramatically lose life due to the overclock for eg. lets take a E1400 LGA775 They are fine to 25% over clock where the CPU sits at CORES:2.5ghz FSB: 1000mhz it will be losing approx. 1/2 of its life at that OC But when we jump up to a 30% which will be CORES: 2.6ghz FSB: 1040mhz the "wear rate" of the cpu is almost 1/2 over the previous OC due to the geometric rate of break down inside of the CPU. meaning it will take around 3/4 of its life off low OC's on tough CPU'S will last just as long as they where running on stock freq, for EG the E1400 is a very strong cpu and will easily take a beating, running at 20% OC will hardly take any life off it, its just when you jump up just that little more things start to brake down 10x faster its sort of confusing. i hope you understand
Oh well...My CPU won't last a 1000 Years, just 500. >_> Your right.
Yeah, my pc said that there was an error but it was just windowed after startup, but not a blue screen. It didn't smoke or overheat though. I won't do it again just for sure. XD.
zack247 Muscelz4 years ago
wow, you got a pentium D that high? my board doesn't even allow overclocking, too bad since 4.4ghz is pretty fast.
Not bad at all! Runs in the same temp range as mine does. Don't feel bad about the voltage thing. I hate raising it, but it's a necessary evil.
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