Overclocking your CPU/GPU

Games, Gaming and Hardware
Welcome to the guide to overclocking your CPU or GPU! With some amazing contributions from our own members here (Kalganized, Plusfour, and more) I've managed to pull together their information on how to overclock your system to be more effective into this thread. For the most part, the thread will follow the outline as seen below. While it's not word for word right now, you'll find all of the information you need to get a good start to overclocking your system.

Mostly I want that outline to stay because, let's face it, it looks sexy.


Introduction

  • What is overclocking?
  • What can you overclock?
  • Is it safe to overclock?
  • What about warranties?
  • Why should I overclock?/When should I overclock?
  • (When) is it worth overclocking my CPU/GPU?
  • How much risk is involved when overclocking a CPU/GPU?
  • What are some of the risks when overclocking a CPU/GPU?
  • What system/parts should I have before considering overclocking?
  • Other important things to consider before overclocking.


  • Overclocking your CPU

  • AMD
  • What processors are overclockable? (Is my processor overclockable?)
  • What are the best processors to overclock?
  • What are the steps to take when overclocking my AMD processor?
  • What should I watch out for after overclocking, to make sure it's successful and not hurting my system?
  • How should I treat my system after overclocking? (General maintenance that I should be doing)
  • Intel
  • What processors are overclockable? (Is my processor overclockable?)
  • What are the best processors to overclock?
  • What are the steps to take when overclocking my Intel processor?
  • What should I watch out for after overclocking, to make sure it's successful and not hurting my system?
  • How should I treat my system after overclocking? (General maintenance that I should be doing)

  • Overclocking your GPU

  • nVidia/ATi
  • What cards should I overclock/not overclock with?
  • Are some cards better to overclock with than others?
  • Does the brand/maker of the card matter? (EVGA/ASUS/Gigabyte/etc.)
  • What are the steps to take when overclocking my nVidia/ATi graphics card?
  • What should I watch out for after overclocking, to make sure it's successful and not hurting my system?
  • How should I treat my system after overclocking? (General maintenance that I should be doing)
  • There is a fair amount of redundancy to the questions, but really I assume you would want to know about the same thing for each card/cpu type, but then I don't really know anything about overclocking either the GPU or CPU, so for all I know, there could be important questions that need to be addressed.

    If you can answer any of these questions, or even a part of the questions, post on this thread and help us out!

    Again, let me know if you have anything to ask/comment about - I'd be more than happy to change things around, add things, take things away, or even scrap the thread if I get enough "this just isn't going to happen" or "just look at tom's hardware for information" responses. Again, all feedback is welcome.
    Introduction

    Alright, so you've made it into this thread, which is awesome! I hope you help contribute to this thread by asking any questions you have, especially if it's about clarification on any of the terms used in this guide, as it is undoubtedly a question someone else is wondering, too. Keep in mind that this is here to try and help even the most novice of computer user, who is at least interested in overclocking, understand more about what it is, what it can do, how to do it, and anything else you should know before overclocking.



          So what is overclocking?

    Overclocking is, to put it simply, making either your CPU (Central Processing Unit) or GPU (Graphics Processing Unit) run faster than when you bought it. Your CPU/GPU, when you first bought it, came "clocked" at a certain speed, and overclocking increases the "clock" or what it's "clocked" at, which allows you to get a few percentages' worth of performance out of your CPU/GPU.


          What can I overclock in my computer?

    Primarily, your CPU and GPU is overclocked. However you can also overclock your motherboard - as a way to overclock the CPU with locked multipliers - but this can be dangerous. RAM can also be overclocked, but this takes a lot of trial and error and has far less leeway and far less tolerance to error than CPU / GPU does in trying to make it go beyond default values. While it is hard to make it go faster in raw speed sense, you can optimize it through XMP profiles / manually modifying RAM settings such as command rate.


          Is it safe to overclock?

    Yes and no. Each CPU and GPU families have different tolerance for overclocking, and to make this issue even more exasperating, each individual CPU and GPU cores have different tolerance for overclocking.

    To make matters even more confusing, CPUs have what's called "stepping". This lesser-known information often can mean quite a bit of difference in how well a CPU can overclock or not.

    Ultimately, some CPU / GPUs can deal with overclock quite well (due to efficient architecture or tech used), while some can't. For example:

  • CPU - Intel Core2Quad Q6600 stepping B3 had heat issues that prevented user from overclocking it all that much. However, G0 stepping of Q6600 overclocks real well since they fixed that issue.
  • GPU - GeForce 480's heat problem was so much that overclocking it is pretty much out of the picture. In a contrast, GeForce 460, which was a cut-down version of original Fermi architecture used in 480, can overclock pretty well.

        • What about my warranty?

    Most shops will not honor warranties if they find out that you broke your CPU / GPU due to overclocking. However, they have no way of knowing this, so the key is don't let them know. ;)

    Some shops, however, do offer warranties no-questions-asked even if a CPU or GPU dies due to overclocking. For example, Intel recently began offering overclocking protection plan for Sandy Bridge CPU users. XFX also used to (not anymore) offer replacements for GPUs that died due to overclocking.


          Why/when should I overclock?

    Generally, it is not necessary to overclock. The results gotten by overclocking varies depending on what CPU / GPU is in use. But for those who want to gain that 1% more performance, it may be worth it.


          What are some of the risks associated with overclocking?

    One of the more important things to know about overclocking, if you're considering it, is that it will shorten the lifespan of your CPU or GPU. While this isn't so much a risk as a guarantee, it is definitely something you face when overclocking your computer.

    The second risk is also something to seriously consider before overclocking your computer: if you change the settings without knowing the limits of your CPU/GPU, you can kill it. You will not pass go, you will not collect 200$, you will go straight to depressingville.


          What system/parts should I have before considering overclocking?

    For CPUs, a good cooling system is a must. Stock fan+heatsink combo doesn't cool all that well. Good third-party cooling system includes CoolerMaster Hyper 212. For users that can't fit such tower-style CPU coolers, closed-loop liquid cooling system is available, such as Corsair H80.

    For GPUs, find cards with custom cooling solutions installed. One such example is ASUS DirectCU series / MSI TwinFrozr type of graphics cards.

    For either CPU or GPU, if you want to try overclocking even higher, a custom water loop setup is required. Effort, time, and money required for this will put off many, however.



    Note: This introduction is a continuous work in progress! Please add any additional thoughts/comments/explanations and let me know where you think they should go!

    Credit where credit is due for this introduction: Kalganized (edited by Myxxi)
    Overclocking your CPU: Intel

    Obviously by this point, you've made it past the scare-factor of the risks (congratulations! that part scares me ._.) and you're ready to learn more about CPU overclocking. Before we hop straight into what you can and can't overclock and how to actually overclock, you should probably know some of the general information when it comes to overclocking your CPU:

    First, you need a good motherboard. You might have noticed on some motherboards, you have bunch of cylindrical / blocky objects near where CPUs will be. These are CPU phases, and have close relation to how much juice it can give/handle for the CPU. Yes, cheap motherboards can overclock too. Just... not a whole lot.

          What CPUs can I overclock?

    Most mid-range motherboards can support decent amount of overclocking. Both AMD and Intel CPUs have specific "unlocked" CPUs that have CPU multiplier/ratios unlocked, so you can -increase- them beyond default value in BIOS. These models are:

  • AMD: All Phenom II models with BE suffix (IE) Phenom II 955 BE), and all FX CPUs
  • Intel: i5 and i7 CPUs with -k suffix (IE) i5-2500k)
  • All other models have locked multipliers that can go down, but can't go up beyond the default value.

    You might remember that I said earlier that motherboard overclocking was possible -- that is a way used to overclock CPUs that are multiplier locked. Once again, this is dangerous and strongly not recommended as you are changing the board clock. This affects not only the CPU, but RAM and graphics card too. There are a lot of variables as to how well this method will work. So don't bother trying this unless you've done a thorough research for all your parts.


          Simple method of overclocking an Intel Sandy Bridge CPU

    1. Google general overclock range people are using for your CPU. For example, i5-2500k is generally taken to 4.0~4.2 GHz.

    2. You enter BIOS.

    3. Change CPU multiplier value to the desired level of overclocking. In case of i5-2500k, you will change 33x to 40x ~ 42x. In case of Phenom II CPUs, since board clock runs at 200 MHz, your multiplier is half the "expected" speed. For example, 17x = 3.4 GHz.

    4. Reboot.

    You are done.
    Wow, that was easy!


          What to keep an eye out for when overclocking your CPU

    1. Temperature, temperature, temperature! Overclocking makes your CPU (and GPUs too) generate a lot more heat.

    Each CPU families have different maximum thermal limit. If a CPU reaches this level, it will start to throttle itself to control heat. A most common result of this is: You are playing a game, then all of sudden, FPS drops to ~5 FPS. Overheating CPU is one of the possible reason why that is happening.

    If CPU is unable to control heat even with throttling, it will force shutdown the system.

    In the past, overclocking can be even scarier as some CPUs didn't even come with self preservation method. Athlon XPs would happily run at maximum speed then die. At least that's not a problem anymore.

    Sandy Bridges generally have recommended maximum limit of ~72C, with absolute max being ~105C.

    Check online to see what is the thermal limit of your CPU. You want to aim for below recommended maximum limit, not absolute maximum.

    Just because Windows seems to have booted fine doesn't mean your overclock is fine temperature-wise. Run CPU stressing programs like Prime95, LinX, and others to see if your CPU can truly handle 100% load for more than 15 minutes. If there are errors or your system is crashing, either: CPU can't handle that level of overclock, CPU needs more juice, or CPU is heating up too much.

    **You can use HWMonitor to monitor CPU temperature.

    2. CPU vCore. vCore is a word to describe how much voltage your CPU is receiving. Generally, motherboards can deal with this pretty well on Auto, but some motherboards overcompensate and give CPU more juice than it should be. Different CPUs have different recommended maximum vCore limit. Google your CPU to find out.

    You can check vCore value in real-time through CPU-Z or HWMonitor.


          What to do if you want to heat your household using just one computer

    (Also known as MUST OVERCLOCK THIS FURTHER!)
    When you find whatever level of overclocking isn't working for your CPU, it's time to increase vCore value -- either through direct vCore value change, or through offset option. Increase this little by little.

    Google and double check for sure what is the maximum recommended vCore value for your CPU. If you go over this, something terrible can happen to your CPU. For Sandy Bridge CPUs, you want to stay below 1.40v.

    Each motherboard has different method of controlling how vCore is distributed, so consult your motherboard manual for more information.



    Note: This post on overclocking your Intel CPU is a continuous work in progress! Please add any additional thoughts/comments/explanations and let me know where you think they should go!

    Credit where credit is due: Kalganized (with some editing by Myxxi)
    Overclocking your CPU: AMD

          General Information on AMD Processors

    AMD Athlon 64. Athlon II, Phenom and Phenom II CPUs overclock similarly to prior AMD processors. A main referance "bus"(often called the FSB, but it technically isn't) with a default speed of 200, having a series of multipliers for cpu clock and actual bus speeds. Phenom II "Black Edition" (commonly "BE") processors have an unlocked CPU multiplier, they are made for overclocking and are obviously the most desirable. It is much easier to overclock with a BE processor since you can leave the main reference clock close to 200 and not worry about memory OC at all. The non-BE Phenom or Phenom II's (or any of the Athlon line) are still able to be overclocked, but it takes more work to set up and you need a more "enthusiast-friendly" motherboard to adjust all the multipliers - or else you will be overclocking the memory too much, which is harder to get stable and usually not necessary.


          Knowing your build

    If you are building from scratch for overclocking, it is relevant to know how AMD "classes" and numbers their CPUs. (as far as I know they have always done it this way) All AMD CPUs having the same core type and stepping (ex. Deneb core C3-stepping) are the same chip, produced in large runs and then tested. Seeing as how millions of transistors are formed on the chip, they do no all turn out equal. The CPUs are tested similarly to what we do with overclocking, to find which chips will run what speed with what voltage. Chips that do better are given higher model numbers and sold set at higher clocks. The most popular Phenom II's for overclocking are probably the 955 and 965 x4 Black editions having the later "C3" revision(125w). That is not to say others are bad, these were just the best ones during the height of Phenom II overclocking's popularity and are also as much as you need to spend to reach top performance. The vast majority of C3 Deneb x4s run at 125w and these are normally recommended for a quad core build. 1055T and 1065T are popular x6 Phenom II processors, although 6 cores is typically seen as overkill for gaming since few games take advantage of more threads(chips with less cores are typically clocked higher to begin with). Higher numbered models are technically a better chip, but are most often already pushed pretty far and have similar max overclocks to slightly lower models. Many vendors are running out of the lower numbered chips since AMD has moved on to producing the FX-series chips.


          Recommended Hardware

    You need a good CPU heatsink for overclocking, even without touching voltages. The stock AMD heatsinks that come with Phenom and Phenom II CPUs are decent, but won't keep you safe over standard Phenom II speeds. The Cooler Master Hyper 212+ is very popular and fits on AM2(+) and AM3(+) sockets - for the money, this is about the best cooling you can get without going to liquid cooling or something huge(er). There are also water cooling options that come prefilled and intended for internal mounting that are easy to set up. If you're building for overclocking, you want good cooling and an unlocked multiplier.


          Starting out overclocking

    Generally for the beginner, leave the clock at 200, leave the voltage on default or "Auto" and adjust the CPU multiplier, .5x at a time(or smallest increment), until the system becomes unstable, then back it off. Before you start, get a program that lets you monitor your temperatures. HWmonitor is a commonly recommended free program, although there are many more advanced monitoring programs like AIDA64 if you want to pay a little money(AIDA64's "stability test" is not as good as anything I will mention for that). Per AMD, the "Maximum operating temperature" of most Phenom IIs is 55C - 62C. That is not to say that your CPU will instantly become blue-smoke at those temps, but to avoid damage you should make sure your processor never reaches them! Searching for your CPU's model number on http://www.cpu-world.com/ will tell you many things including max temp and supported voltage. Programs like CPU-Z, AIDA 64 and others will tell you your chip's exact model and stepping if you don't know it.

          Stability in your Overclocking

    There are many ways to check stability. Booting into windows is the first test, but does not mean you're in the clear! Monitor your CPU temps throughout any testing. The The most obvious test is to simply use the programs/games that you need to use. WoW can find memory problems that memory testing programs cannot! :) Being able to run benchmarks like PCmark or 3Dmark without crashing shows some degree of stability. Specific programs can me used to stress your CPU and memory. MemTest86 is not as good as it used to be for checking memory overclock (and it takes many tests over a very long time). There are stress tests like Prime95 which make your processor continuously do math at 100% to stress it, using variable amounts of system RAM. I found Prime95 to be the most demanding test you can run, (the most likely test to make it crash, especially if you let it use a lot of memory). It might be dangerous to run Prime for days on end like some people do, surviving an hour counts as stable for most people. ("24/7 Prime95" used to be heard in forums a lot, but it's really pretty darn stable if it lasts an hour) "Linx" or "Intel Burn Test" can also be used for this, completing these extremely harsh "benchmark" tests with multiple passes will stress your system at least as much as Prime will(usually faster too). Make sure any of these programs you use are running as many threads as you have cores. Hyper-PI is a program that will run multiple instances of the popular "SuperPi" benchmark simultaneously on all cores - calculating the max 32 million digits of pi is a pretty good test if run multiple times at once like this. All of these programs are more "stress test" than they are "benchmark" and can help verify your overclock as stable and cool.


          Maximizing your CPU via overclocking

    In order to "go all out", a stable memory overclock is usually achieved first with a low CPU multiplier before going into finding the right CPU speed. AMD CPUs reportedly respond better to memory overclocking than Intel CPUs, but again this requires more BIOS options and more risk. (if OC'd memory at similar cpu clock does not improve superpi or other cpu benchmarks, then your memory is already fast enough) Specificaly, low memory latencies(timings) have much more of an impact here than on Intel systems - DDR3 with CL7or8 or DDR2 @ CL4 helps a lot(CAS Latency is usually the first and most important number in memory timings as in "8-8-8-24" - lower is better for these #'s). It is generally recommended to choose quality RAM with a low CL (CAS Latency) of the speed you want and keep memory overclocking to a minimum. The overall latency is not always linear with timings and can be measured with certain programs (PCmark and AIDA64 include this test).

    Going over the recommended voltage for RAM modules is not usually necessary and not a good idea in general. In Phenom systems, the DDR2 and DDR3 memory contollers are inside the processor chip, and the relevant memory controller will have its own voltage setting in BIOS. These are more important to stable memory than the DDR voltage itself. Being on-chip, altering these voltages increases load on the CPU heatsink.
    Overclocking the memory speed is usually only noticeable in benchmarks and is less necessary for games.

    It can get confusing since different motherboards' BIOS's use different names for voltage and bus settings, be sure to resarch your specific board before you mess with it! It is common to leave the referance clock near 200 but increase the multiplier for the "northbridge frequancy" - this often effects memory latency as much as the actual timings. It is important to note that this NB bus is separate from the HyperTransport link, HT-Link should be adjusted to be as close to stock as possible on AMD systems - this is easier to do if the reference clock is near 200.

    Memory speeds have for quite some time exceeded the demands of most programs. For CPU-intensive applications and games, keeping the overall memory latency as low as possible usually gives more improvement than the actual "speed" of the memory on a Phenom II system. The memory "command rate" can often be set to either "1T" or "2T", adjusting how often the CPU accesses the memory. 2T command rate increases stability, but 1T is faster(although not as much faster as it should be) running CR2 is fine if you are overclocking the referance clock, or running an unsupported memory configuration(for Phenom II, filling all 4 slots of DDR2 1066, or running any DDR3 over 1333 is technically unsupported).

    Overclocking programs can adjust your reference clock within Windows(like nvidia control panel in some cases). It looks nice on screenshots to have exact whole numbers in CPU-Z, but it often seems to be more stable to stick with whatever the BIOS gives you, even if it ends up not being the exact whole number you set it to.



    Note: This post on overclocking your AMD CPU is a continuous work in progress! Please add any additional thoughts/comments/explanations and let me know where you think they should go!

    Credit where credit is due: Plusfour (with minimal editing by Myxxi) <strong/> <strong/>
    Overclocking your GPU (both nVidia and ATi)

    Thankfully, overclocking your GPU is a lot easier than overclocking your CPU. Your graphics card is usually installed with a control panel to assist you with all of the settings, which helps a ton. As per Kalganized, there are these main methods of overclocking your GPU:

    1. Through nVidia control panel / AMD Catalyst control panel. Your options are limited here, but should generally ensure you don't overclock too much.

    2. Through third party programs such as MSI Afterburner (and many variants based on this), Sapphire TriXX, nVidia Inspector, and more. These allow you to overclock a lot further than the nVidia / AMD control panel lets you, and also configure how fan ramps up, as well as vCore for the GPU.

    3. Through GPU BIOS editing. Not recommended.


          I'm ready to overclock, let's get this started!

    Hold your horses! Not all graphics cards are equal. I strongly recommend against overclocking any low-range graphics cards, as they come with low-end fans and won't cope very well with heat.

    As long as you have entry mid-range (Radeon 6770 / GeForce 550 Ti) at least, it should be OK.

    Also, google for the general range of overclock done for your card / family. You need to know safe range for them before you begin.


          Alright then, do some cards overclock better than others? Does the company that makes the card matter?

    As mentioned, this depends on GPU family, GPU itself, and the card (and the fans used).

    Generally, all major graphics card vendors such as ASUS, EVGA, Gigabyte, HIS, MSI, XFX, Sapphire all produce special cards optimized for overclocking. They are often more costly than other cards of same family.

    Some of these cards include:

    ASUS DirectCU series
    MSI TwinFrozr / Lightning series
    EVGA SuperClocked series
    HIS IceQ series
    Sapphire Toxic series

    These overclock-friendly cards are generally all situated at high-end market, with some at higher-mid range cards such as Radeon 6870 / GeForce 560.


          How do I do the actual overclocking of my GPU?

    This part's pretty easy. Through either method you want to increase the GPU speed and VRAM speed to the level you want, and then you click apply. Bam, done.

    Note by Kal: The new speeds will kick in when you use 3D programs. Also,
    for AMD users, it's recommended to increase PowerTune to 20%+ or beyond (for some cards). nVidia does not currently have something like this.


          So what should I watch out for?

    Once again, temperature. While GPUs can handle temperature punishment better than the CPUs, it doesn't mean you should let them go 100C+. Generally, you want to keep them below 90C if possible, lower the better.

    Well-known GPU torturing program includes Furmark, but it is said both nVidia and AMD automatically detect this program and throttle the cards so it'd never burn out. Just run usual suites of games and see how your temperature holds out.

    Use HWMonitor or GPU-Z to monitor the temperature.

    You will want to ramp up the fan speed if you want to overclock.

    GPU vCore does not increase beyond the maximum you set. You can increase vCore value to see how much further your GPU can be pushed, but this depends on GPU families and individual GPU / card itself. Google to see how far your card can possibly be pushed.



    As a side note, when overclocking Nvidia GPU's.

    The default Nvidia fan profile is TERRIBLE. I found my GPU approaching its "maximum safe temperature" (according to NVidia themselves) while the fan was still turning at a measily 30% of max.

    That being said - If you are going to attempt to overclock your GPU, I reccomend you get the program MSI Afterburner (not just for MSI cards/motherboards) and use that to set up a MUCH more agressive GPU Fan profile. Yes, you'll get more fan noise from the card, but you'll also reduce the risk that your 200-600$ video card will go up in smoke, literally.


    Also - The Core i7 (first generation socket 1366) CPU's can easily be overclocked. I've got my i7-920 (2.67ghz stock) running quite stable at 3.8ghz, and acutally turned the v-core DOWN.

    I do reccomend NOT using stock cooling if you're going to try to overclock. Corsair makes some nice H series CPU coolers that are self-contained watercooling. Check out the H-60, and h-80.

    ~Raewynn

    Note: This post on overclocking your GPU is a continuous work in progress! Please add any additional thoughts/comments/explanations and let me know where you think they should go!

    Credit where credit is due: Kalganized (with some editing by Myxxi), Raewynn
    Reserved for a miscellaneous information.
    Bottom-line of overclocking is, IMO:

    Overclocking is now easier than ever, and it doesn't take long to find out the general level of 'safe' overclocking for your hardware. Depending on the hardware, overclocking can give you good boost in gaming for free. You can't deny that awesome feeling that it only took a bit of overclocking for your CPU or GPU to match the levels of more expensive hardware.

    However, judge for yourself if that performance increase is worth the potential risk. For me, it's worth it. For you, it may not be. Good CPUs and GPUs aren't cheap, after all. It only takes a little mistake, unpreparedness, or just plain bad luck to see hardware worth hundreds of dollars just go poof.

    ~Kalganized
    Also as a final reserve:

    Ode to Kalganized

    Your help is needed
    For this forum is dead with
    Out your expertise

    I suck at Haikus
    Excellent work you are doing for the community, Myxxi :)

    Here is the general information to fill in your table of content:

    * What is overclocking:

    To put it in a simple term, you make either CPU or GPU run faster than the default clock that it came with. It is done to gain few more % of performance out of it.

    * What can you overclock:

    Primarily, CPU and GPU.

    You can also overclock motherboard actually -- as a way to overclock CPU with locked multipliers. However, this can be dangerous.

    RAM can also be overclocked, but this takes a lot of trial and error, and has far less leeway and far less tolerance to error than CPU / GPU does in trying to make it go beyond default values. However, while it is hard to make it go faster in raw speed sense, you can optimize it through XMP profiles / manually modifying RAM settings such as command rate.

    * Is it safe to overclock:

    Yes and no.

    Each CPU and GPU families have different tolerance for overclocking, and to make this issue even more exasperating, each individual CPU and GPU cores have different tolerance for overclocking.

    To make matters even more confusing, CPUs have what's called "stepping". This lesser-known information often can mean quite a bit of difference in how well a CPU can overclock or not.

    Some CPU / GPUs can deal with overclock quite well (due to efficient architecture or tech used), while some can't.

    For example:

    CPU - Intel Core2Quad Q6600 stepping B3 had heat issues that prevented user from overclocking it all that much. However, G0 stepping of Q6600 overclocks real well since they fixed that issue.

    GPU - GeForce 480's heat problem was so much that overclocking it is pretty much out of the picture. In a contrast, GeForce 460, which was a cut-down version of original Fermi architecture used in 480, can overclock pretty well.

    * What about warranties:

    Most shops will not honor warranties if they find out that you broke your CPU / GPU due to overclocking. However, they have no way of knowing this. Don't let them know. ;)

    Some shops do offer warranties no-questions-asked even if a CPU or GPU dies due to overclocking. For example, Intel recently began offering overclocking protection plan for Sandy Bridge CPU users. XFX also used to (not anymore) offer replacements for GPUs that died due to overclocking.

    * Why / When should I overclock:

    Generally, it is not necessary to overclock. The results gotten by overclocking varies depending on what CPU / GPU is in use. But for those who want to gain that 1% more performance, it may be worth it.

    The usual risks of overclocking:

    1. You will shorten the life of the CPU / GPU.

    2. If you change settings without knowing the limits of your CPU / GPU, you can kill it.

    * What system/parts should I have:

    For CPUs, a good cooling system is a must. Stock fan+heatsink combo doesn't cool all that well. Good third-party cooling system includes CoolerMaster Hyper 212. For users that can't fit such tower-style CPU coolers, closed-loop liquid cooling system is available, such as Corsair H80.

    For GPUs, find cards with custom cooling solutions installed. One such example is ASUS DirectCU series / MSI TwinFrozr type of graphics cards.

    For either CPU and GPU, if you want to try overclocking even higher, a custom water loop setup is required. Effort, time, and money required for this will put off many, however.
    CPU overclocking

    * General information on actual overclocking:

    First, you need a good motherboard. You might have noticed on some motherboards, you have bunch of cylindrical / blocky objects near where CPUs will be. These are CPU phases, and have close relation to how much juice it can give/handle for the CPU.

    Yes, cheap motherboards can overclock too. Just... not a whole lot.

    Most mid-range motherboards can support decent amount of overclocking.

    Now, the CPU: Both AMD and Intel CPUs have specific "unlocked" CPUs that have CPU multiplier/ratios unlocked, so you can -increase- them beyond default value in BIOS. These models are:

    - AMD: All Phenom II models with BE suffix (IE) Phenom II 955 BE), and all FX CPUs.
    - Intel: i5 and i7 CPUs with -k suffix (IE) i5-2500k).

    All other models have locked multipliers that can go down, but can't go up beyond the default value.

    You might remember that I said earlier that motherboard overclocking was possible -- that is a way used to overclock CPUs that are multiplier locked. Once again, this is dangerous and strongly not recommended as you are changing the board clock. This affects not only the CPU, but RAM and graphics card too. There are a lot of variables as to how well this method will work. So don't bother trying this unless you've done a thorough research for all your parts.

    * Simple method of overclocking an Intel Sandy Bridge CPU:

    1. Google general overclock range people are using for your CPU. For example, i5-2500k is generally taken to 4.0~4.2 GHz.

    2. You enter BIOS.

    3. Change CPU multiplier value to the desired level of overclocking. In case of i5-2500k, you will change 33x to 40x ~ 42x. In case of Phenom II CPUs, since board clock runs at 200 MHz, your multiplier is half the "expected" speed. For example, 17x = 3.4 GHz.

    4. Reboot.

    You are done.

    Wow, that was easy!

    Unfortunately, AMD overclocking is slightly different. I will leave that to AMD pros.

    * What to watch out for when overclocking:

    1. Temperature, temperature, temperature! Overclocking makes your CPU (and GPUs too) generate a lot more heat.

    Each CPU families have different maximum thermal limit. If a CPU reaches this level, it will start to throttle itself to control heat. A most common result of this is: You are playing a game, then all of sudden, FPS drops to ~5 FPS. Overheating CPU is one of the possible reason why that is happening.

    If CPU is unable to control heat even with throttling, it will force shutdown the system.

    In the past, overclocking can be even scarier as some CPUs didn't even come with self preservation method. Athlon XPs would happily run at maximum speed then die. At least that's not a problem anymore.

    Phenom IIs generally have recommended maximum limit of 62C, with absolute max being ~72C.

    Sandy Bridges generally have recommended maximum limit of ~72C, with absolute max being ~105C.

    Check online to see what is the thermal limit of your CPU. You want to aim for below recommended maximum limit, not absolute maximum.

    Just because Windows seems to have booted fine doesn't mean your overclock is fine temperature-wise. Run CPU stressing programs like Prime95, LinX, and others to see if your CPU can truly handle 100% load for more than 15 minutes. If there are errors or your system is crashing, either: CPU can't handle that level of overclock, CPU needs more juice, or CPU is heating up too much.

    You can use HWMonitor to monitor CPU temperature.

    2. CPU vCore. vCore is a word to describe how much voltage your CPU is receiving. Generally, motherboards can deal with this pretty well on Auto, but some motherboards overcompensate and give CPU more juice than it should be. Different CPUs have different recommended maximum vCore limit. Google your CPU to find out.

    You can check vCore value in real-time through CPU-Z or HWMonitor.

    * I want to OC further! MOAR SPEEEEEED:

    When you find whatever level of overclocking isn't working for your CPU, it's time to increase vCore value -- either through direct vCore value change, or through offset option. Increase this little by little.

    Google and double check for sure what is the maximum recommended vCore value for your CPU. If you go over this, something terrible can happen to your CPU. For Sandy Bridge CPUs, you want to stay below 1.40v.

    Each motherboard has different method of controlling how vCore is distributed, so consult your motherboard manual for more information.
    You type this as fast as I can edit and repost the information! That's impressive XD

    Thanks a lot for the great start of this thread!

    P.S. - don't feel obliged to do this all at once lol

    Also, just skimming through your post (<---- oh my god I typed thread first there /facepalm - thanks for the amazing start! hahaha), I've noticed a few things mentioned like temperatures, ok ay well mostly just temperatures for right now, but I think I'll add a Miscellany post where people can find the software that's helpful for overclocking? Something like setting up temp monitors on your computer. So if you have any advice on where to get them (preferably for free, but throwing in buy-able, reliable options is always good to know, too) that'd be great!
    GPU overclocking

    This is lot easier than overclocking CPU.

    There are three main method of overclocking GPU:

    1. Through nVidia control panel / AMD Catalyst control panel. Your options are limited here, but should generally ensure you don't overclock too much.

    2. Through third party programs such as MSI Afterburner (and many variants based on this), Sapphire TriXX, nVidia Inspector, and more. These allow you to overclock a lot further than the nVidia / AMD control panel lets you, and also configure how fan ramps up, as well as vCore for the GPU.

    3. Through GPU BIOS editing. Not recommended.

    * How?

    Easy. Through either method, you increase GPU speed and VRAM speed to the level you want. Click Apply. You are done.

    The new speeds will kick in when you use 3D programs.

    For AMD users, it is recommended to increase PowerTune to 20%+ or beyond (for some cards). nVidia does not have something like this.

    * What to watch out:

    Once again, temperature. While GPUs can handle temperature punishment better than the CPUs, it doesn't mean you should let them go 100C+. Generally, you want to keep them below 90C if possible, lower the better.

    Well-known GPU torturing program includes Furmark, but it is said both nVidia and AMD automatically detect this program and throttle the cards so it'd never burn out. Just run usual suites of games and see how your temperature holds out.

    Use HWMonitor or GPU-Z to monitor the temperature.

    You will want to ramp up the fan speed if you want to overclock.

    GPU vCore does not increase beyond the maximum you set. You can increase vCore value to see how much further your GPU can be pushed, but this depends on GPU families and individual GPU / card itself. Google to see how far your card can possibly be pushed.

    * Looks like I'm ready to overclock!

    Hold your horses! Not all graphics cards are equal. I strongly recommend against overclocking any low-range graphics cards, as they come with low-end fans and won't cope very well with heat.

    As long as you have entry mid-range (Radeon 6770 / GeForce 550 Ti) at least, it should be OK.

    Also, google for the general range of overclock done for your card / family. You need to know safe range for them before you begin.

    * So, do some cards overclock better than others then? Does what company that make the card matter?

    As mentioned, this depends on GPU family, GPU itself, and the card (and the fans used).

    Generally, all major graphics card vendors such as ASUS, EVGA, Gigabyte, HIS, MSI, XFX, Sapphire all produce special cards optimized for overclocking. They are often more costly than other cards of same family.

    Some of these cards include:

    ASUS DirectCU series
    MSI TwinFrozr / Lightning series
    EVGA SuperClocked series
    HIS IceQ series
    Sapphire Toxic series

    These overclock-friendly cards are generally all situated at high-end market, with some at higher-mid range cards such as Radeon 6870 / GeForce 560.
    If I'm missing any specific information you'd like to know (besides AMD CPU overclocking), let me know. ;o
    I love the information, thanks again.

    As for anything else I'd wanna know, it'd probably be a "bottom line" when it comes to overclocking. For instance, I was thinking of putting something like

    "The bottom line of overclocking:
    It is not exactly easy
    It involves a fair amount of trial and error
    Be prepared to google things to learn more about your GPU/CPU than you ever expected to
    Don't get frustrated if you mess up!
    etc
    etc
    etc"

    I was wondering if you had anything kinda like that rolling around that you think about overclocking?
    Bottom-line of overclocking is, IMO:

    Overclocking is now easier than ever, and it doesn't take long to find out the general level of 'safe' overclocking for your hardware. Depending on the hardware, overclocking can give you good boost in gaming for free. You can't deny that awesome feeling that it only took a bit of overclocking for your CPU or GPU to match the levels of more expensive hardware.

    However, judge for yourself if that performance increase is worth the potential risk. For me, it's worth it. For you, it may not be. Good CPUs and GPUs aren't cheap, after all. It only takes a little mistake, unpreparedness, or just plain bad luck to see hardware worth hundreds of dollars just go poof.
    Bottom-line of overclocking is, IMO:

    Overclocking is now easier than ever, and it doesn't take long to find out the general level of 'safe' overclocking for your hardware. Depending on the hardware, overclocking can give you good boost in gaming for free. You can't deny that awesome feeling that it only took a bit of overclocking for your CPU or GPU to match the levels of more expensive hardware.

    However, judge for yourself if that performance increase is worth the potential risk. For me, it's worth it. For you, it may not be. Good CPUs and GPUs aren't cheap, after all. It only takes a little mistake, unpreparedness, or just plain bad luck to see hardware worth hundreds of dollars just go poof.


    Thanks.

    Let me know how you feel about the layout of the guide and how easy it is to scan through the information and find what you need. I'm trying to make this as friendly as possible, and I don't want it to seem like walls of text or difficult to find anything.
    Looks good enough for me. ;)

    I'd probably ask people to report your post to get it stickied or something. O_o
    Or it'll be buried down there in the abyss eventually.
    Looks good enough for me. ;)

    I'd probably ask people to report your post to get it stickied or something. O_o
    Or it'll be buried down there in the abyss eventually.


    Thanks x 14! The goal is to have some place where people can point to when someone asks about overclocking or when someone is asking whether or not people wanna overclock at all (I do see you asking a lot about overclocking and whether or not people are interested in it.)
    I also want it to be a place where any questions regarding overclocking anything in the PC are directed; just to have a central place for the entire topic, really.
    02/01/2012 05:41 PMPosted by Mÿxxï
    Reserved - Need an AMD expert for overclocking an AMD processor!
    I dunno about expert, but I might be the only one here who actually does it significantly. What I know might be to specific for this. Lots of people like Phenom II's but they're getting harder to find and have a real likelihood of becoming a lot less popular pretty soon if they finally get the FX-series right.
    I'll write something if you want something specific, or if someone tells me that all the newer CPUs have the same bus/multiplier layout...

    And I talk too much, you'd have to edit it =)
    02/01/2012 10:21 PMPosted by Plusfour
    Reserved - Need an AMD expert for overclocking an AMD processor!
    I dunno about expert, but I might be the only one here who actually does it significantly. What I know might be to specific for this. Lots of people like Phenom II's but they're getting harder to find and have a real likelihood of becoming a lot less popular pretty soon if they finally get the FX-series right.
    I'll write something if you want something specific, or if someone tells me that all the newer CPUs have the same bus/multiplier layout...

    And I talk too much, you'd have to edit it =)


    Heya, any start to the AMD overclocking would be fantastic! If you're wordy, that's even better :) I consider myself someone pretty decent at editing other people's work - or at least decent enough if I put time aside for it. You can see the points I'm aiming to cover, and I'll repost them here, but I would also like to add that I hope you pop in any little thing you can think of, when it comes to the topic of AMD and overclocking. The more information we have to sort through the better. If you're feeling VERY wordy and would feel better just making a word document, feel free to let me know and I can have you send it to my e-mail.

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