An Introduction to Overclocking
Note: All steps in this guide will require specific knowledge of your Motherboard and CPU. Write down the model for both, and search Google for the terms “overclocking [your Motherboard here]” and “overclocking [your CPU here].” Information found from these searches may be critical to the rest of the work you will do in this guide. Also, these modifications are at your own risk. I take no responsibility for anything that happens due to this guide, good, bad, or otherwise.
Intro
So, perhaps you want to turn the new rig you just built into a monster. Maybe you'd like to tweak that 2 year old machine to get some more use out of it. Either way, overclocking could be your best bet. There are many pros and cons to overclocking. Here are a few to consider before moving on:
Pros:
-Cost (free!)
-Speed (isn't that the point?)
-Better Performance (decreased load times)
-Bragging Rights (everyone is jealous of geeks)
Cons:
-Risk (fried CPU anyone?)
-Difficulty (only at first)
-Time (you'd better clear that schedule)
Obviously, there are two sides to the world of overclocking. Still, the results firmly stand out against any negatives.
Research
This is possibly the most important part in the entire overclocking process. Before you ever touch your BIOS, before you ever tweak that PCIE Frequency (no really, don't do that first), you need to read. If you're illiterate, stop here. This shouldn't be a problem though, since you've managed to get this far. Clearly, you're ready to delve into the world of computer components, voltages, and other things that would confuse any sane person. The subjects you'll want to read up on are the basics of overclocking (what the term means, what it does, etc.), why voltages matter, and how to change the BIOS. Google is your friend in this case, and will lead you to all of the pages you could want to read. Just a quick starting point though:
http://en.wikipedia.org/wiki/Overclocking
If you don't wish to read up on overclocking however, I'll make it easy. Overclocking is the process of speeding up a computer by pushing certain components (namely the CPU) to operate at faster speeds than originally intended. This is done by changing clock speeds and voltages on your motherboard through a tool called a BIOS. If you don't know how to access the BIOS, pack up, go home, and buy a faster computer online. Without basic knowledge of the BIOS (how to access it anyway), true overclocking is impossible. This is in no way meant to belittle anyone, but if you're lost at this point, you really don't want to mess with fragile settings.
I'd also like to point out another overclocking issue. There happens to be software on the market which claims to overclock your PC with little to no effort. Avoid this if possible. ASUS and MSI even include such software with some of their motherboards. While it may do the job, most of this software does not have any way to prevent a user from doing serious damage. A BIOS on the other hand, will often fail to boot if it sees a setting which is far too skewed from others.
This would be a good time for you to download a few tools, as well. CPU-Z, RealTemp, Prime95, and IntelBurnTest (known as IBT) are all tools you really MUST have for this process. Best of all, they're all free.
Warning
The rest of the steps here could be dangerous to follow. If you proceed, then you understand and agree that I am not responsible, and will not be held liable for any damages caused by following this guide or modifying computer settings. This is not meant to scare people off, but I would like to ensure that the danger of a “worst-case scenario” is pointed out. BIOS modification MAY cause hardware damage, fires, magic smoke, rising of the dead, and World War III. Most of are not likely, but they are possible.
Dirty Work
Well, if you've followed this guide and done the required research so far, you should be well versed in overclocking by now. You know that the BIOS requires the computer to be rebooted, and that a certain key must be pressed to open it. This means that you won't be able to look at this guide while in the BIOS unless you print it or have it open on another computer (a laptop is helpful here). That brings me to another point. For the most part, laptops cannot be overclocked. I highly recommend against trying this. Leave the tinkering to your poor, defenseless desktop.
For the purposes of this guide, I'm going to reference Intel equipment, more specifically the Intel i7 950 processor, set to 3.07GHz clock speed from the factory. This guide's specificity may hinder the efforts of many potential overclockers, but read on, I insist. You will still learn something relevant. I would also like to sincerely apologize to AMD fans. I love you all equally.
So, the first thing to do is to boot into BIOS. Go ahead, I'll wait. Done? No? Hmmmmm. Oh, you're ready now? Ok. Now that you're in the BIOS, you'll want to look for CPU settings. They should be in one of the main tabs. You'll want to read through all of the settings here (PLL, PCIE Frequency, NB, SB, and Memory Timing to name a few). Once you're acquainted with this page, and have WRITTEN DOWN THE STOCK SETTINGS IN CASE OF AN EMERGENCY, it is time to start entering some numbers. For now, any settings on Auto can probably stay as such. You'll want to turn off any “helper” features on your processor. These may include, but are not limited to CPU and PCIE Spread Spectrum, C1E, A20M, HT/HyperThreading, and Intel Speed Step (this step is obviously different for AMD products, but Google can tell you what to change). These may be fine for stock processors, but yours is about to leave that realm. Also, enable Load Line Calibration if it is disabled. Now, you'll want to find your CPU Frequency (may be labeled as BCLK Frequency). Raise this to the highest multiplier allowed (for example, an i7 950 has a max CPU Frequency of 200). Now find the CPU Ratio Setting (may be called multiplier) and set it to the lowest odd number possible (for example, the same i7 950 has a lowest odd multiplier of 13). These settings are simply a baseline test to see if your processor and motherboard can handle high clock settings. Now you can attempt to boot back into your standard operating system.
If this process works, and you boot back into the operating system, hooray. You've just (sorta) overclocked your computer. It is more likely that you've really underclocked the processor, but for now, this is unimportant. You may, however, have failed to boot, or gotten into, lets say Windows, and seen a Blue Screen of Death. This isn't a problem. It just means something in the BIOS didn't agree with your hardware. All this really tells us is that your motherboard or CPU can't handle the highest possible frequency (this may mean you'll be stuck with a smaller overclock than you'd like, but possibly not). In either case, you may now boot back into BIOS. At this point, we will look into actual overclocking of your computer, and how to get the most out of it. Since your processor is likely to be a different model than mine, and may even be produced by a different manufacturer (*gasp!*) the techniques to follow will vary.
Foremost, when changing settings for the first time, aim low, then steadily move the bar higher. What I mean is this: if you start with the highest clock speed and multipliers, the overclock will probably fail. In fact, it might burn up the processor. By starting low, you are finding your way upward from stable ground. Pick a number that sounds good in your head (and is in the allowed range of the processor) for each of the two main settings, and enter them. Try to boot. Did it work? Likely the answer is no (it was always disappointing on my first time too...). Lower something, and try again. Then again. And maybe even one more time. Eventually, it WILL work, to some degree. If the computer boots, but upon login, it crashes, this is okay. In fact, this is where you want to proceed to the next phase. Now it is time to change your CPU voltage. Another note here, never come ANYWHERE near max for this setting. It will result in nuclear holocaust and the deaths of many puppies. You don't want to kill puppies, now do you? On second thought, don't answer, we'll just move on. The CPU Voltage is really the key to stability for an overclocked computer. Too low, and it will fail to boot, or crash. Too high, and you'll cook the computer. Start with the stock setting here (or the mean of the max and min values if stock = auto) and work your way up VERY VERY SLOWLY. We are talking about changing the hundredth or thousandth decimal value (1.0XX0, where the X's are what you change). Once your computer will boot, and you can log in, open RealTemp. If your temperatures are above 80C, shut down immediately. Temperatures in this range are not acceptable for an idling computer. In this case, lower the clock, multiplier, or voltage. You're really looking for temperatures of no higher than 65C. Repeat this process until an acceptable temperature is achieved. Once you can boot, and RealTemp is in the specified range (<=65C), open CPU-Z. Towards the middle/bottom left, there is a box labeled core speed. This is the speed of your processor. Near dead center is a box labeled Specification. At the end of this is a number in GHz. Move the core speed decimal 3 places to the left to get your rough GHz. This is how you compare whether you are overclocked or not. If the core speed GHz is higher than the Specification GHz, congratulations, you overclocked your computer. If not, go back to the BIOS and keep playing. Just don't change any of the auto settings unless you really know what you're doing, or someone on the internet has proof that such settings must be changed.
Stabilizing
Once you've reached a suitable point where your computer will stay booted, it is time to see if your settings are really stable. This is done by running RealTemp along with Prime95. Open both, then in Prime95, make sure Blend is selected, and click OK. If the temps reported by RealTemp climb into the 90C range, again this is dangerous. Shut down immediately. Change some settings (lower vCore/voltage or decrease your frequency), and try again. You should know, your computer will certainly bog down from this test, if not crash. DO NOT attempt to run other programs while testing, as they only increase heat, and compound the situation. If it does crash, you'll need to work on stability. The following is a good thing to include when asking for help in online forums:
Code:
Ai Overclock Tuner.....................[Manual] CPU Ratio Setting......................[23.0] Intel(r) SpeedStep(tm) Tech............[Disabled] Xtreme Phase Full Power Mode...........[Enabled] BCLK Frequency.........................[192] PCIE Frequency.........................[100] DRAM Frequency.........................[Auto] UCLK Frequency.........................[Auto] QPI Link Data Rate.....................[Auto] CPU Voltage Control....................[Manual] CPU Voltage............................[1.38750] CPU PLL Voltage........................[Auto] QPI/DRAM Core Voltage..................[Auto] IOH Voltage............................[Auto] IOH PCIE Voltage.......................[Auto] ICH Voltage............................[Auto] ICH PCIE Voltage.......................[Auto] DRAM Bus Voltage.......................[Auto] DRAM DATA REF Voltage on CHA...........[Auto] DRAM CTRL REF Voltage on CHA...........[Auto] DRAM DATA REF Voltage on CHB...........[Auto] DRAM CTRL REF Voltage on CHB...........[Auto] DRAM DATA REF Voltage on CHC...........[Auto] DRAM CTRL REF Voltage on CHC...........[Auto] Load-Line Calibration..................[Enabled] CPU Differential Amplitude.............[Auto] CPU Clock Skew.........................[Auto] CPU Spread Spectrum....................[Disabled] IOH Clock Skew.........................[Auto] PCIE Spread Spectrum...................[Disabled] C1E Support............................[Disabled] Hardware Prefetcher....................[Enabled] Adjacent Cache Line Prefetch...........[Enabled] Intel(r) Virtualization Tech...........[Enabled] CPU TM Function........................[Enabled] Execute Disable Bit....................[Enabled] Intel(r) HT Technology.................[Disabled] Active Processor Cores.................[All] A20M...................................[Disabled]
For ease of others, just make sure to include the “code” tags around it when you post (plus it looks cool). These tags can be found in the text formatting options just above the text box on a normal forum. Now, I certainly can't tell you what settings will make YOUR computer stable, but someone, somewhere on the internet, can. Ask around on forums (such as GND-Tech.com), and you are sure to receive plenty of help. There are many people with systems similar to your own. Once you have settings you feel are stable, try to run Prime95 for a minimum of 12 hours, with nothing but it and RealTemp running (and keep an eye on temperatures for the first 10 minutes). If it doesn't crash after this extended run, you're golden. If it does, keep looking for answers online, or try changing a few settings on your own. While an extreme overclock may be stable enough to browse the web, running it long-term could severely shorten the lifespan of your components. Making your system stable is the last, and single most important step to properly overclocking your computer.
Overview
So, now you have learned a bit about the basics of overclocking, why it matters, and how one might go about doing it. Perhaps you've even read this far without doing any of the steps I listed, and you simply wanted to know what this was all about. That's cool too. In any event, I hope you've emerged wiser, and can adapt this new-found knowledge to benefit yourself, or at least make someone else (even me) feel less knowledgeable.
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