The Beginner’s Guide to CPU Overclocking
To some, the term overclocking conjures up images of fried motherboards and exploding CPUs. To others, it’s commonplace. In reality, the process of overclocking either your CPU or GPU is simple and safe. Best of all, it can provide a significant performance boost.
There are, however, a few concerns you should consider when overclocking your CPU. Here is a guide to show you the ins and outs of CPU overclocking, and how to do so in a calm and safe manner.
But before you dive in, if you don’t quite know what CPUs are or how they work, then we highly recommend starting with our beginner’s article on CPU basics .
A (Very) Brief Overview of CPU Overclocking
The clock in overclock refers to the clock speed of a computer component. Clock speed is indicated in Hz (Hertz), and dictates the general speed of a component.
A slew of other factors determine the actual speed of your PC. Among others, that includes CPU cores, cache size, and generation. The latest gen CPUs are also much more efficient than older models. Moreover, CPU limitations are defined by external components, such as motherboard and cooler.
Should I Overclock?
The tech enthusiast in me wants to say “Why haven’t you overclocked your PC already?” There is, however, a method to the madness of overclocking and a variety of factors to consider.
Unlocked Clock Speed
Certain Intel and AMD CPUs support unlocked clock multiplier. This function allows you to increase your clock speed by changing your clock multiplier (more on this below). A few examples of unlocked CPUs are AMD’s FX Series and Intel’s K series.
These are not the only CPUs which support overclocking. To be clear: clock speed is a changeable parameter in any CPU, but it is often limited by your BIOS. CPUs with unlocked clock multipliers also allow for better voltage control, clock speed control, and overclock software support.
What may not be worth the extra effort, is attempting to overclock your locked CPU by flashing a different BIOS versions, upping your stock fan RPM, slapping an extra fan in your case, and pushing the limits of your non-optimized motherboard.
Rule number one of PC tweaking: understand and accept the limits of your hardware.
One of the reasons CPU overclocking is less popular than GPU overclocking is cooling.
GPUs come equipped with their own heat dissipating and cooling technology. This allows users to overclock their GPUs without having to worry about overheating the component.
CPUs do not provide the same level of cooling at stock. We don’t recommend stock coolers, even under regular CPU loads. Once users begin experimenting with CPU voltage, temperatures can increase exponentially. This is why an upgraded CPU cooler is not only helpful, but downright necessary, when it comes to legitimate CPU overclocks. Yet, with a careful eye, respectable CPU overclocks using stock coolers are achievable.
Turbo Boost/Core Technology
Let’s say you have an Intel Core i5 4460 processor in your PC, and you’d like to squeeze a little more juice out of your processor. I know my i5 4460 has a base clock of 3.2 GHz, so maybe I’ll attempt to increase it to 3.3 GHz. There’s only one problem.
The CPU already runs at that speed. How? Through a piece of technology called Turbo Boost for Intel CPUs and Turbo Core for AMD CPUs. Turbo Boost or Core operate by adjusting clock speed dynamically, allowing for more performance of a single CPU core when under load. This means the base clock of your CPU may be 3.20 GHz, but can perform at a higher clock speed. Keep this in mind if you’re only thinking of adjusting clock speeds slightly; you may not even need to!
Danger! High Voltage
Overclocking is more an art than a science. First, the user increases the clock speed. This first process will, in itself, increase the heat of your CPU. Once you hit a stability limit, the dance isn’t over. You’ll need to increase the voltage to match the performance increase of your clock speed.
A lapse in judgement concerning CPU core voltage is the main cause of worry with overclocking. Voltage, unlike clock speed, hinges on both the power capacity of your CPU and the voltage capabilities of your motherboard. Since your motherboard supplies the power to your CPU, you must ensure that your motherboard can handle the load.
Gigabyte, for example, has an Overclocking motherboard series built to handle higher voltage loads than otherwise. They also provide durability rating to ensure said capabilities. The same is not true for all motherboards, so err on the side of caution when adjusting voltage settings for your CPU.
The problem with standardizing overclock settings is the large range of flexibility with overclock speeds. Stable overclock speeds don’t just range from generation to generation. They range from CPU to CPU. That’s why a standard overclock which works for all CPUs is impossible to find. The only way to truly overclock your CPU is to modify parameters, stress-test, rinse, and repeat.
The process may become fairly tedious, especially if you’ve never overclocked before. I would advise you take your time, and not rush the process. After all, even a slight overclock will provide you speeds you otherwise wouldn’t have.
Overclocking: A First-Hand Guide
The purpose of this article is not to explain the relationship your CPU has to the rest of your computer. The aim here is to provide a step by step walk-through to overclocking your PC. Remember, you can always benefit from learning more about the inner workings of your PC.
Overclocking Terms and Parameters
Certain terms are vital for overclocking purposes.
- BCLK (Base Clock or Frequency) refers to the base speed (in Hertz, or cycles per second) of your processor. Overall clock speed does not occur in a chunk. Instead, your CPU (along with your RAM) runs in clock cycles, often referred to as its frequency. Most base clock run at 100 MHz. The overall speed of your CPU is indicated by the base clock multiplied by the clock multiplier.
- The Clock Multiplier is the main parameter you will change during overclock. This parameter dictates the general speed of your CPU. For example, a BCLK speed of 100 MHz and a clock multiplier setting of 32 will have an overall clock speed of 3.2 GHz or 3200 MHz.
- VCore, the CPU core voltage. When you are overclocking your PC, ensure that your are modifying your core voltage (as opposed to DRAM voltage, for example). You can check this parameter using monitoring software like HWMonitor or CPU-Z. At first, don’t modify VCore. After you’ve hit a snag with stability, begin increasing your voltage by tenths (.10s). The moment your PC crashes due to a VCore parameter change, switch it back.
Overclocking With Software
The software works as a bridge between your hardware and your overclock. I recommend these software choices for users just starting out with component overclocking.
They provide an easy-to-use interface, live monitoring software, and necessary parameter limits to stop you from doing anything rash. If you already have benchmarking programs at your disposal, and are familiar with stress-testing, the better choice would be to enter into your BIOS and make the necessary changes there.
Overclocking With Your BIOS
Most PCs nowadays come equipped with cleaner BIOS interfaces than the ones of yester-year. Before, BIOS options were text based and provided minimal information regarding changeable variables. Today’s BIOS settings are more informative and useful. BIOS settings differ from model to model. Search for your motherboards manual online to match the instructions below with your BIOS’ equivalent.
Search for the overclock settings in your BIOS. Since I am using an MSI motherboard, I will be using the MSI BIOS screen. Older BIOS versions will not include a clickable BIOS, but will often support the same parameter changes.
One thing to notice before entering your overclock (OC) settings. On the top left-hand corner of the screen, you’ll see a button labeled OC Genie. OC Genie is unique to MSI motherboards, and it is an example of a canned overclock feature present in some BIOS options. Canned overclocks promise better performance with the push of a button.
To be clear: OC Genie does its job. It will overclock your CPU. Yet, the ease does come at a price. OC Genie will spike your voltage higher, thereby heating your component more than necessary. Also, it doesn’t efficiently gauge your clock speed. I recommend you go the route of trial and error, rather than place your overclock in OC Genie’s hands. The same goes for other canned overclock programs.
Click on the OC button of your BIOS to access your overclock settings.
You will note that my OC settings are missing a key parameter: VCore or Voltage. Compare this BIOS with the following.
Using a Gaming motherboard, i.e. one designed for overclocking, like the Z87 series from MSI and/or an unlocked CPU, will provide a wider range of overclocking capabilities. Locked processors, in conjunction with optimized BIOS versions, will limit the parameters you can change. The general practice of overclocking, however, does not change from CPU to CPU. If you have a locked CPU, either roll back your BIOS or use an unlocked processor to enable default voltage settings.
Step 1: Disable Turbo Boost / Core. You can do so by mousing over the Turbo Boost / Core parameter and clicking Disable. Since Turbo Boost and Core create an offset with voltage and CPU ratio, it is difficult to test the raw stability of any given overclock. The same goes for disabling any canned overclocking programs like OC Genie.
Step 2: Locate your CPU Ratio. Don’t confuse this with Base or Adjusted frequency. Your CPU ratio is a two-digit parameter which, when multiplied by your Base Frequency, creates your adjusted CPU Frequency. This number indicates the general speed of your CPU. Adjust this parameter by single-digits, i.e. a 33 CPU Ratio to 34. If, after stress-testing, your PC crashes, lower the parameter.
There is a trick to changing BIOS parameters. The [Auto] parameter gives a preset list of choices to choose from, or much enter your own parameter into the list. The Auto parameter, on the other hand, indicates that you can enter a numerical value. To change, mouse-over the parameter and type in your value. Most users click on this parameter to no avail. You must enter the value yourself. You can also change this setting by using the + / – keyboard commands. If a value you enter automatically reverts to a lesser value, your CPU is locked.
Step 3: If you hit a ceiling with your CPU Ratio, begin increasing your default voltage by .025 V. Stress-test and repeat until you hit a bump in stability. Do not scale your voltage wildly. Voltage caps hinge on multiple aspects of your rig, including CPU sockets and motherboard capabilities. This makes voltage changes the most dangerous parameter to modify. If you start slow and ensure a thorough stress-test, you have nothing to worry about.
How I Learned to Stop Worrying and Love My BIOS
There is a tendency to think overclocking a PC requires that the user study huge tomes regarding Computer Engineering. Overclocking, as has been shown, amounts to a little more than slightly opening the gates of power from your CPU. Have no fear, proceed safely and unlock the potential of your CPU!
Do you overclock your CPU? What’s your method? Let us know in the comments below!