20 replies to this topic

[mihapiha]

ALL CHANGES ON YOUR OWN RISK! Remember that we do not take responsibility for any damages and that overclocking will make your warranty of your hardware void!


This basic How² should explain how most BIOS-chips work and what you need to know before you start overclocking.


What do I need to overclock my CPU?

With any CPU overclock many components within your computer are effected. First of all your CPU, then the power-supply-unit, which has to be able to handle the extra wattage the CPU now needs, then the CPU-cooling, which now has to handle the bigger heat. Most the time the motherboard must be able to handle the new configuration as well as the memory. The motherboard as well as the memory heat can go up as well, and more cooling might be needed for either components.

What happens when I overclock my CPU?

The mentioned components above are effected in different ways. More details form point 1 onwards:
A reminder of the effected components:

• CPU
  
• PowerSupplyUnit
  
• Motherboard
  
• Memory
  
• CPU cooling
  
• Motherboard and Memory cooling

1 - The basic vocabulary and math necessary for the OC



1.1 - The basic vocablulary


The first thing you have to know is how to calculate any CPU frequency in order to judge how far you can get and where the reason for instability probably lies. The Intel CPUs have something called FSB (FrontSideBus) which is the bus that carries data between the CPU and the NB (North-Bridge) and it is essential to calculate what happens with the components.

The FSB of the CPU is four times the FSB of the MB.

So if you have a Intel Core2Duo E6600, the FSB of the CPU is 1066 MHz and the FSB of the MB is 266 MHz.
If you have a Core2Quad Q9550, the FSB of the CPU is 1333 MHz and the FSB of the MB is 333 MHz.

With this information you should now understand why a Core2Extreme QX9770 with a FSB of 1600 MHz does not run on every MB.
Many MB do not support that high of an FSB.


1.2 - The basic math


The FSB connects MB, memory and CPU with each other. Depending on the FSB the memory frequency has to be high enough. If you use DDR2 the memory multiplier is two, if you use DDR3 the memory multiplier is three.

Now lets get to our three examples:

• The Core2Duo E6600 has an FSB of 1066 MHz, a MB frequency of 266 MHz. If now DDR2 memory is installed, the minimum required memory frequency is twice the FSB of the motherboard. Meaning:
  266 MHz (FSB) x 2 (memory multiplier) = 533 MHz (DDR2 memory frequency required)
  and 266 MHz (FSB) x 3 (memory multiplier) = 800 MHz (DDR3 memory frequency required)
  
  
• The Core2Quad Q9550 has an FSB of 1333 MHz, a MB frequency of 333 MHz. Meaning:
  333 MHz (FSB) x 2 (memory multiplier) = 666 MHz (DDR2 memory frequency required)
  and 333 MHz (FSB) x 3 (memory multiplier) = 1000 MHz (DDR3 memory frequency required)
  
  
• The Core2Extreme QX9770 has an FSB of 1600 MHz, a MB frequency of 400 MHz, so the DDR2-800 MHz or DDR3-1200 MHz are required.

These are the minimum memory frequencies required for your system, but usually that is not enough if you intend to overclock. DDR2-1066 MHz or DDR3-1600 MHz are recommended for any OC.


1.3 - The CPU basics


Now lets go to the CPU. The CPU has it's own multiplier too. The multiplier variates between the different models though, however the CPUs in any series are completely the same. The reason for that is, that when CPUs come out of the factory, it is not yet determent which CPU will become an expensive Extreme-model and which will become the cheapest CPU in the series.

So a cheap Q9300 may be right next to a expensive QX9770, because all chips are different. Now all those chips, which don't have names yet, go into testing. There now the test shows which CPU works well under which frequency. If however Intel has to many great CPUs (meaning the all would be QX9770s) and they know they won't be able to sell them for these high prices, they just lock the multiplier to a low number. These CPUs overclock fantastically well. So it is the luck of the draw if you get a good or bad CPU, one that overclocks well or one that doesn't overclock at all.

Now the multiplier of the CPU variates. To explain how the frequency is determent I'll use the three examples I used before.

• The E6600 with his FSB 266 MHz has a maximum multiplier of 9. Meaning: 266 MHz (FSB) x 9 (CPU multiplier) = 2400 MHz (CPU frequency)
  
• The Q9550 with his FSB 333 MHz has a maximum multiplier of 8.5. Meaning: 333 MHz (FSB) x 8.5 (CPU multiplier) = 2830 MHz (CPU frequency)
  
• The QX9770 with his FSB 400 MHz has a multiplier of 8. Meaning: 400 MHz (FSB) x 8 (CPU multiplier) = 3200 MHz (CPU frequency)

In order to get a higher CPU frequency, we have to raise either the multiplier or the FSB. The multiplier is locked on all Intel CPUs which don't have the name "Extreme", so the FSB is usually the only option. If you are the lucky owner of a Core2Extreme CPU you can now jump to point 3.3.

So if we are now forced to overclock over the FSB it means the memory frequency as well as the motherboard frequency will rise. This also means there will be more reasons why any frequency might not be stable. Because if the FSB rises, the memory frequency does so too.

[mihapiha]

ALL CHANGES ON YOUR OWN RISK! Remember that we do not take responsibility for any damages and that overclocking will make your warranty of your hardware void!



2 - The basic OC



2.1 - The effects


Because we will rise the FSB, the motherboard frequency will rise too. However it also means the memory frequency will be rising too. So not only does your motherboard, CPU, power supply and cooling have to be able to handle the changes but the memory as well.

To avoid multiple reasons for instability while overclocking, we try to overclock one piece of hardware at the time. This can be accomplished by lowering certain values. First we lower the multiplier to insure that the frequency of the CPU is not a factor and to maximize the FSB since the multiplier can be raised later anyways. To get back to our two examples (QX9770 fell out of this process):

• The E6600 with his FSB 266 MHz and a new multiplier of 6. Meaning: 266 MHz (FSB) x 6 (CPU multiplier) = 1600 MHz (CPU frequency)
  
• The Q9550 with his FSB 333 MHz and a new multiplier of 6. Meaning: 333 MHz (FSB) x 6 (CPU multiplier) = 2000 MHz (CPU frequency)

Since all these CPUs are able to handle higher frequencies than the one we just set, we can be assured that the CPU is no longer a factor for instability if we would raise the FSB to for example 350. Because:

• The E6600 with the new FSB of 350 MHz and a new multiplier of 6. Meaning: 350 MHz (FSB) x 6 (CPU multiplier) = 2100 MHz (CPU frequency)
  
• The Q9550 with the new FSB ot 350 MHz and a new multiplier of 6. Meaning: 350 MHz (FSB) x 6 (CPU multiplier) = 2100 MHz (CPU frequency)

While the FSB went up the frequencies still stayed under that what the CPU is capable of according to Intel specifications


2.2 - The memory


Now we made it possible for the CPU to be no longer a factor in this matter. The FSB can be risen without the CPU being the problem. However the memory may still run beyond his capabilities. As you read in point 1.2 you now know which memory you need for a specific CPU. As we now overclock a faster memory capable of higher frequencies is necessary.

The only exception here is, if you are the lucky owner of a MB with nVidia chipset, which allows the memory frequency to stay unlinked to the FSB. Meaning the FSB can rise and the memory frequency will stay approximately the same.

If you don't have MB with nVidia chipset you'll have to have a memory capable of higher frequencies.

For overclocking a DDR2-1066 MHz and DDR3-1600 MHz have become more or less a standard. Higher frequencies are of course always an option.


2.3 - The motherboard


Depending what motherboard you have, and what chipset the motherboard has, certain FSB levels can be expected. A big disadvantage is, if your motherboard has an onbord graphic chip. The onboard-GPU limits the overclock and maximum FSB drastically. Also remember that the temperature of your motherboard will rise, so be sure to add cooling if necessary.

I will list now the FSB level that most chipsets can reach to my personal experience. Also it should give you a quick overview what FSB frequencies you can expect from the motherboard. Keep in mind that it may vary, and this is just a quick check for some basic judgment on the hardware you have before you go ahead and overclock:

• nVidia nforce 650i chipset --> FSB 450
  
• nVidia nforce 680i chipset --> FSB 500
  
• nVidia nforce 750i chipset --> FSB 450
  
• nVidia nforce 780i chipset --> FSB 470
  
• nVidia nforce 790i chipset --> FSB 500
  
• Intel P35 chipset --> FSB 500
  
• Intel X38 chipset --> FSB 500
  
• Intel P45 chipset --> FSB 650
  
• Intel X48 chipset --> FSB 600

[mihapiha]

ALL CHANGES ON YOUR OWN RISK! Remember that we do not take responsibility for any damages and that overclocking will make your warranty of your hardware void!


3 - The practical part of the OC



3.1 - The preperation


In order to prevent any bigger problems, save stable bios settings, so that you don't have to remember all the changes you made.

3.1.1 - The CPU

This guide will of course vary between each and every single system and this is only my preferred way to get started. The more time you'll take for your overclock and the more you test your hardware, the more easy it is to find errors or any signs of instability, and that will insure later a very stable and high overclock.

First thing I like to do is to eliminate possible problems. If you go ahead and just rise the FSB and you end up with a blue screen, it is harder to find the reason for the blue screen. The first problem I like to eliminate is the CPU. By lowering the multiplier a huge thing has been done. You can raise the multiplier anyways later, after you has found the maximum frequency for your motherboard and your memory.

But there are other factors that may cause a problem with the CPU. The first is called EIST or Speedstep. This function lowers the CPUs multiplier if the CPU is idle and not stressed. This saves power, produces less consumption and heat, because it also drops the VCore (CPU Voltage). While this sounds good, it causes instability during any OC, since all the temperatures and voltages have to be kept as constant as possible.

All the precaution things, I mention now can be later activated again once the FSB came to it's highest value. You will however have to test if any of these things costs stability and have to be left deactivated.

So EIST/Speedstep is one the first on the list of things that has to be deactivated. The second is C1E or C2E. This is a function that controls and checks the CPU temperature. Since the CPU is going to run out of it's specifications this might cause problems. Also I like to deactivate all other power saving things your CPU and your bios might offer.

At last I like to insure that the motherboard does not adjust any voltages and set the standard value for my CPU prior the next step. You can do that by setting the VCore to the Intel CPU's specification and activate in the bios something called "Loadline Calibration" or disable something called "Vdroop". It basically does the same, and leaves the voltages relatively constant while the CPU is under load or idle.

3.1.1 - The memory

To insure the memory's stability I like to set the memory stock setting as they are given by the manufacturer. For this you should set the stock timings of your specific memory as well as the stock DRAM-voltage. You can find these informations on the manufacturer homepage, or even better: Just look on the sticker of your memory. It should give you all the informations needed.

If you have a high-end memory which can handle a very high frequency, I'd also lower the frequency of the memory by decreasing the memory ratio. The memory always runs in a certain ratio to the FSB. By changing the ratio or memory multiplier, you can decrease or increase the memory frequency.

The ideal memory frequency before the start of the overclock is usually twice (for DDR2) or triple (for DDR3) of the FSB.


3.2 - The maximum FSB


As now everything is prepared for the overclock, we can now address rising the FSB in small steps. I would recommend a jump of 10 MHz each time, and then go towards testing these setting in Windows.

Stability testing is an essential part. I recommend using Prime95, LinX or IntelBurn to stress the CPU to it's maximum. While doing that you have to keep an eye on the CPU temperatures. This can be done with simple tools like CoreTemp or RealTemp. Make sure that the temperatures don't surpass Intel specifications.

I would recommend stress testing approximately for 15 minutes and checking the temperatures while doing so. If the system is "stable" and the temperatures stay within the specifications, you can rise the FSB for another 10 MHz.

At some point you should experience some sign of instability. Either a blue screen, Windows freezes or one of the stress test programs has an error.

This means some settings in your bios are not ideal in order for new FSB. If your CPU frequency stayed under it's stock frequency and the memory frequency under it's stock frequency, you can be sure that the problem lies with the motherboard. The motherboard can not handle the high FSB anymore.

To make the motherboard run stable with the high FSB you will have to adjust motherboard voltages. By a raise of the NB-Voltage or SB-Voltage (south-bridge voltage) or the motherboard voltage itself, you can insure that the FSB will be stable from that point on. A voltage increase is followed by a heat increase, so make sure you have sufficient cooling for your motherboard.

You may be forced to try for several hours to find the right voltages in order to be able to keep increasing the FSB. At some point you will not be able to increase the FSB anymore. It can be that your memory, CPU or motherboard simply can't do more. The overclock is always as weak as the weakest link out of the components effected by the overclock.

I would personally recommend that you would now lower the FSB for 5 or 10 MHz to absolutely insure that the new high FSB is really stable.


3.3 - The maximum memory frequency


You now reached a high FSB, and now it's time to check if you can get any more speed out of your memory. By raising the memory multiplier or memory ratio the frequency can be risen. I would recommend to stay under the memory specifications though.

Many people worry that the memory is now not as fast anymore, because it is forced to run a bit under it's specifications after the FSB overclock. This may be true in some few incidents, but generally, because of the increased FSB, the memory as well as CPU and motherboard are faster under these conditions. So you don't need to worry if your memory now runs 70 MHz lower than it should. It should still be faster than it was before.

As always test every change in the bios with a stress test under windows.

If you feel you want to adjust some more, you can still try to lower the memory timings while keeping the system stable.
Try to avoid raising the DRAM voltage (to increase memory stability), because the chips tend to get used to the voltage after a certain time and won't work with their stock setting anymore, or keep demanding more and more voltage to keep them stable.


3.4 - The maximum CPU frequency


From here on the rest es easy. By raising the multiplier of the CPU (CPU clock ratio) you can now overclock your CPU. Remember that each raise of the multiplier will raise the CPU frequency by the FSB you have reached. This means it means, that it could be, that the instability issues appear much more drastically then they came with the FSB overclock.

If you encounter stability problems with any stress test program, blue screen or the PC doesn't start, you'll have to reset the settings you've saved and raise a single voltage: the VCore (CPU Voltage).

Remember that your core temperature should not surpass the Intel specifications.

Edited by mihapiha, 04 February 2010 - 01:03 PM.

[mihapiha]

ALL CHANGES ON YOUR OWN RISK! Remember that we do not take responsibility for any damages and that overclocking will make your warranty of your hardware void!



4 - Pros and Cons of Overclocking



Pros:

When you establish a stable OC, your PC will work faster and you may save money by Oc'ing a budget CPU to perform much faster than even a $999 stock CPU!

Games, app's even most of the other PC hardware will work faster!

Although an OC'ed CPU needs more cooling, in most cases for a simple 10-20% OC, even a budget $20 CPU cooler will be fine over the stock cooler offered by AMD_Intel. For more radical OCs more expensive - complex cooling may be required.

Cons:

Any form of OC of your CPU RAM and MOBO will shorten the lifespan of those components, In theory at stock they should all last 5 years even a mild OC can shorten that runtime to 3 years. A very high OC can shorten the runtime to 1-2 years. So this is worth bearing in mind. The better the components and or cooling the less the effect should be. Budget RAM will often burn out much faster under OC than Quality RAM.

Your CPU RAM and Mobo warrenties can void the moment you OC. Check with the maker of your CPU RAM and Mobo (even if they offer OC options) how OC'ing your rig may affect the warrenties in your territority before you OC. Look at their forums or ask their tech support about how does OC affect warrenty and what limits do they place.



5 - Conclusion



If you did everything right, your CPU temperature should stay under the Intel specifications and your CPU multiplier has come the maximum value of your CPU.

Remember, that this is only a basic guide and not something that would or will apply to every system. Every system and every CPU is different, and you will find most answers from the forum staff, other users as well as myself, when we address you to your specific problems and needs.


Now go ahead and open a new topic, tell us exactly what hardware you use and we'll help you as soon as possible!

Edited by mihapiha, 02 February 2010 - 03:37 AM.

[jfrydom]

Didn't read it yet but looks great. Easier than trying to explain it off the top of ones head.

[LightPhoenix]

It looks great!

After I updated my bios I will take pictures for you!

[LightPhoenix]

I took some pictures for you!
But I need to go to the barber right now so after it I will upload them for you.

[mihapiha]

LightPhoenix, on Feb 2 2010, 12:02 PM, said:

I took some pictures for you!
But I need to go to the barber right now so after it I will upload them for you.

Great thanks. Upload them and send me the Links via personal message. I haven't come to the translation of the Core i7 OC yet, but hopefully I will be able to address that topic in this week.

That topic will be pinned as well, as soon as I feel it's ready, you'll all see it here...

[HaCkEr]

STICKYYYYYYYYYY PLEASE

[mihapiha]

HADES - The gamer within, on Feb 2 2010, 02:17 PM, said:

STICKYYYYYYYYYY PLEASE

What do you mean? The topic has been pined to the top, if that's what you mean...

[HaCkEr]

mihapiha, on Feb 2 2010, 07:49 PM, said:

What do you mean? The topic has been pined to the top, if that's what you mean...

oops... sorry dint notice that.. and yeah thats what i meant by "STICKY"
And can u make one on OCing the Athlon II's and Phenom II's please

its not urgent... just do it after u do the intel thing

Edited by HADES - The gamer within, 02 February 2010 - 03:16 PM.

[mihapiha]

I don't know if I can do an AMD based one because I simply don't have the experience with overclocking AMDs...

[HaCkEr]

mihapiha, on Feb 2 2010, 09:42 PM, said:

I don't know if I can do an AMD based one because I simply don't have the experience with overclocking AMDs...

ohhhhhhhh too bad for me

[Revorocks]

AMD CPU's are exactly the same as the Intel ones except you have a Hyper transport link and you can raise the multiplier on the Black edition CPU's.

Awesome guide there, should really help loads of people to start overclocking!

Edited by Revorocks, 02 February 2010 - 06:45 PM.

[LeighPing]

Awesome guide.

[.Chris]

I just read the whole thing, brilliant guide! I'm still a pretty noob OCer and I definitely learned a lot!

Keep up the awesome work! PM me the pictures that you need and i'll have them tomorrow.

[LightPhoenix]

Mihapiha, I sent you some pictures of my bios some months ago. Did you have time to make a overclock guide for me?

[mihapiha]

Time yeah. But I'm laking motivation... It's sill on my "What I have to do"-list...

[wumpus]

this looks good man! Nice job!

[Rolandz]

nao do one 4 Memory,im a total noob on Memory and it would really help to have a tutorial on it as thorough as this one