Learning how to overclock, even just at the most basic level, will help you unlock the full potential of your gaming rig. There are myriad ways you can improve the performance of your PC, but most of them are going to cost you. Learning the basics of overclocking though means squeezing the maximum performance out of your existing components, in your favourite games, without spending a penny.
Tweaking your GPU’s clockspeed can improve even the best budget graphics card.
So, learning the basics of how to overclock your CPU or GPU can boost your frame rates for free, sometimes making the difference between unplayable and playable, but what actually is overclocking?
If you’ve ever seen any pictures or videos of overclocking events you’ll have seen liquid nitrogen splashed liberally across the floor, pouring clouds of vapour up into the air and serious-looking guys (it’s always guys) in logo’d t-shirts either high-fiving each other or frantically prodding at keyboards and strange contraptions atop test benches. It would be very easy to look at all that and conclude overclocking is something best left to the experts.
But that’s not really overclocking, at least not the true spirit of overclocking. It’s not some dark art, it’s not some chase for ever-higher, ever more meaningless index numbers and it’s not some competitive sport. Overclocking is a way for us to squeeze as much performance as we can from the components in our PCs when we can’t afford to go out and buy something newer or something faster.
PCs and their constituent parts are expensive, but technological progress waits for no man and so this year’s high-flyers can become next-year’s poor cousins incredibly quickly. Even the GTX 1080 Ti will one day look pedestrian against a mid-range GPU of a newer graphics generation.
But overclocking is a way to keep your ageing rig in touch with the latest games and run them at a decent frame rate - and all without opening your wallet.
Where once it was a question of replacing crystals, swapping silicon or drawing lines on your CPU with a pencil (honest) now you just need some overclocking software, some BIOS-fu and a little bit of patience.
Super-serious disclaimer time: Overclocking is far less dangerous to the health of your components than it used to be - with failsafes built into most modern silicon - but you will still be running your hardware outside its officially rated parameters, putting it at risk. That means you’ll likely invalidate any warranty your hardware might still have and there is a slight risk that any extra stress might just push it over the edge and brick it. That's why historically overclocking is done on aging components. You have been warned...
Right, now the official warning stuff is out of the way let’s get down to business. The business of making your gaming PC even more awesome, starting with how to overlock your graphics card.
1. Overclocking software
The first step whenever you want to do anything to your PC is to make sure it’s completely up to date. That ought to either flag up any gremlins lurking in your system or help get rid of them before they become an issue. Check Windows Update to get your OS up to date and ensure you have the latest drivers for your graphics card, whether it's an AMD or Nvidia GPU.
Next you’ll want to grab your overclocking software. My personal choice for perking up your graphics card is MSI’s Afterburner software, and its latest release now includes monitoring for DirectX 12 titles too. It uses the classic Rivatuner backend (like Asus’ GPU Tweak and EVGA’s Precision apps), but comes with an easy-to-use interface and a handy on-screen display to keep track of things in-game. It’s a free download, takes only a few minutes to install and can be used on any GPU, not just those from MSI.
As well as the software for enacting any overclock you want to achieve you should get yourself some benchmarking applications too. Have a look in your Steam library, you may find some of the games you already own have built-in benchmarks, I mean, everyone’s got a copy of GTA V right? But, while games are great for giving you a tangible before and after shot of your PC’s performance, they’re a bit awkward to use when you’re trying to find the limits of your hardware.
I’d suggest downloading the Unigine Heaven benchmark. It’s a GPU-intensive 3D rendering test which will stress your card with a continuous loop you can run in a window on your desktop. And it looks kinda purty too...
2. Benchmark baseline performance
So you can actually tell what you've achieved through your overclocking efforts you need to get some baseline performance numbers for how your rig currently performs. Benchmarking is a rather dry, tedious process (welcome to my world), but it will allow you to feel all warm and fuzzy after you’ve nailed down your extra GPU performance because you can see in black and white just what all that overclocking effort has afforded you.
Grab one of your favourite games with a built-in benchmark - we use the likes of GTA V, the Total War games, Shadow of Mordor, Hitman and the latest Tomb Raider - and then run the test (usually found in the graphics options) at your current settings, noting down the final average and minimum frame rate scores. It’s also worth benchmarking the Heaven test at your monitor’s native resolution too (hit F9 and sit back). You could also download the free version of 3DMark and run the basic FireStrike test to get a reliable index score.
3. Fun with frequencies
I can’t stress this enough - be patient. That’s the key to getting the most out of your GPU with the sort of basic overclocking we’re looking at here. You’re very unlikely to do any damage to your graphics card while you’re testing its limits, but if you go in heavy-handed, pushing the clocks up as high as the sliders allow, the minimal risks are definitely increased.
First, boot up Afterburner and make sure the little Windows logo isn’t lit up - clicking that button ensures the current boosted settings are applied when the system boots up. You don’t want that happening when you’re trying to find the limits, only when you’re sure the system is stable.
Next, boot up Heaven in a window, one that’s small enough so you can view and access the Afterburner control panel while Heaven is looping through its floating medieval village scenery. On a 1080p screen, run it at 720p, and 1080p on a 1440p or 4K panel.
Now you’re ready to start tweaking and the best place to start is with the memory clocks. Start shifting the memory slider to the right in 5-10MHz increments, hitting the tick button to apply the boost each time. After each step check the looping Heaven run for visual artifacts appearing on-screen. Memory glitches will manifest themselves as either solid blocks or blobs of colours or pin-sharp stars. Keep pushing the memory slider up in small increments until you start to see those telltale signs of failing memory...or until the card or system crashes.
Once you get to that stage it’s time to dial back the clockspeed by either one or two steps, apply the new memory clock and leave Heaven running for a longer period to make sure it remains stable at the new speed. If you see more memory artifacts drop down another 5-10MHz step and test again.
Now you’ve found the memory limits note down the stable clockspeed offset and reset the card to its default settings.
4. GPU overclocking
This is where the real performance-changing stuff goes down, and also where you’re going to start generating the most heat. Before you start upping the GPU clockspeed itself push the power limit slider up to max - allowing the graphics card to deliver more power to the silicon if it can - and also push up the temperature limit a little higher to account for the increased heat generation.
Using the same process we used when overclocking the video memory, push the GPU clockspeed up by 5-10MHz increments, checking the game window for artifacts as you apply each step change.
Processor artifacts manifest themselves in different ways to memory issues. Keep an eye out for pixel-sized dots of different colours appearing around the screen, random shards of colour or bright, coloured fullscreen flashes. As soon as you see anything like that it’s time to dial back the GPU clockspeed in the same way as you did with the memory to find the stable boosted clockspeed.
5. The full GPU overclocking package
Now you want to see how things look with both the GPU and memory clocks set to the peak levels you discovered individually. Don’t be surprised if putting both the sliders up to where you found they operated stably earlier now results in lots of artifacts or crashes. If that happens (and it probably will) take note of whether the glitches you see relate to either GPU or VRAM and knock back the relevant slider by one 5MHz notch.
If you just get a system crash, on the other hand, simply reboot and set both memory and processors speeds back one step and test again. When you feel confident about your settings it’s time to stress test.
6. Test and test again
Close down Heaven in windowed form and restart it fullscreen at your native resolution and leave it looping for a good ten minutes to make sure it remains fully stable at your new clocks. When you are positive it is stable hit F9 to benchmark and see what performance increase your efforts have afforded you. Now replicate your earlier gaming and 3DMark tests to see what else you’ve gained.
Finally, hit that little Windows logo on Afterburner and light it up so that every time you boot you’re running at your newly discovered, overclocked settings.
7. It’s not as fast as I’d hoped…
Not all graphics cards are created equal and neither are the chips inside them. You cannot be guaranteed of a particular overclock (or indeed any overclock at all) as every GPU will have a different limit because of vagaries in the manufacturing process. We've also heard of issues with later GTX 1070 cards, using Micron instead of Samsung memory, that limits their memory overclocking performance compared with the original memory modules of the Founders Editions.
You might get lucky and find your GPU will boost like a beast, similarly you might not be able to get much extra performance at all, but as certain accidental horse-flesh suppliers are wont to say: every little helps.
There are other things you can do to help, however. If your card is a reference version, using either a standard Nvidia or AMD cooler design, then you can buy relatively cheap third-party coolers to replace them and potentially deliver higher overclocking performance. Corsair even offer adapters so you can attach one of their closed-loop CPU water-coolers to your graphics card, though that is maybe going a little too far if you’re just trying to eek out another few months of gaming from your aging GPU.
8. AMD WattMan
Using Afterburner, or other Rivatuner-based applications, isn’t the only option. With AMD Radeon cards you can simply use the new WattMan tool which now comes as part of the Radeon Settings driver software.
It's a dedicated option for modern AMD cards and allows you to do per-application overclocking for individual games. Below the latest 400-series cards you won't have full access to everything that WattMan can offer (thanks to Danteska for pointing that out), though you will still be able to play with some sliders.
The overclocking process is similar to that which I detailed earlier - patiently pushing up clockspeeds while checking Heaven in a window - but there are a few slightly different steps. First you need to raise the minimum and target fan speeds, then switch from auto to manual and increase the temperature targets. Again though you will need to push the power limit to maximum before you tweak the clocks.
For the memory you need to raise ‘State 1’ in small increments and hit apply to check stability while the GPU slider needs to be raised in 0.5% steps instead of the 5-10MHz jumps we used in Afterburner.
Once more though it’s all about patience and vigilance.
1. Prep work
Overclocking your processor is a slightly different bag of chips to boosting the performance of your GPU, though the basic principles remain the same: be patient and take things steady.
There is one other thing to remember and that’s to pick your battles. Not every processor can be overclocked anymore. Intel put the brakes on that a while back by locking down the clockspeed multipliers on all but their most expensive SKUs. You need to make sure your CPU has an unlocked multiplier to be able to post serious performance boosts. For Intel that means picking a K-series chip and for AMD any of its latest Ryzen CPUs or their older Black Edition parts - hit Win+Pause/Break keys together to display what's in your current rig if you can't quite remember.
Check out our guide to the best CPUs for gaming for our take on the top processors around right now. They just happen to also be the ones that are most comfortable with having the clocks tweaked too...
You’ll also need some other software to help you out, but once more it’s all available for free. First you’ll need more monitoring software and I’d suggest picking out CPU-Z to keep an eye on the real-time CPU clockspeed and multipliers and also Real Temp to keep track of the temperatures inside the processor package.
The simplest CPU benchmarking tool is Cinebench; it’s a multi-threaded processor-based rendering test which will stress your silicon and spit out an index score at the end to help gauge relative performance. Finally download Prime95 to stress test your CPU once you’re happy with the final clockspeed.
You can also download Intel and AMD-based overclocking software if you want to run everything from the safety of Windows, using either Intel XTU or AMD OverDrive. AMD's new Ryzen CPUs even have their very own Ryzen Master software specifically designed for the new chips, though you will have greater access to the different settings of your AM4 board going through the BIOS rather than the more basic software. When you come to testing too, using the Ryzen Master application takes up around 10% of your CPU's resources, so always shut if down if you're benchmarking how well your overclock has taken.
But personally I always find it just as easy to do everything from within the old-school confines of your motherboard’s BIOS. And also because it’s mostly keyboard-based you can pretend you’re like some hacker out of a mid-90s TV show or clueless Hollywood blockbuster.
2. Stay fresh, stay frosty
Once again you need to make sure your PC is fully up to date. That doesn’t just mean Windows update and general driver stuff, you also want to make sure your motherboard BIOS is the latest firmware. To do this you’ll need to find out the exact make and model of your current motherboard as well as what BIOS version you’re currently running. Handily the CPU-Z app you’ve just downloaded will help if you don’t know off the top of your head.
Boot up CPU-Z and click the Mainboard tab across the top. In the screen which pops up will be the manufacturer and model of your board as well as what BIOS version is currently installed. Armed with this knowledge you can head off to the manufacturer’s website, search for your board and download the latest firmware BIOS update.
It’s not worth messing around here - you need to find the EXACT match between BIOS and board. Simply downloading one which looks about right won’t be enough. Chances are the BIOS will reject it, but at worst it could brick your motherboard completely. Beware. Once downloaded, unzip the BIOS update to a USB stick and reboot with your pendrive in place.
Hitting either F2 or Del when the PC POST screen appears (before the Windows loading screen loads up) will take you into your BIOS screen. From there you’ll likely have to go into the Tools tab. What BIOS you see will differ on a manufacturer-to-manufacturer basis, but they’re all broadly similar. You ought to find a BIOS update utility which will take your downloaded firmware update and guide you through the process.
3. Completely automatic
Once your BIOS is updated you’ll want to reboot back into it from fresh and find the option to load the optimised settings. This is basically like a factory reset for your motherboard, but will be tied to the latest firmware you’ve just installed so it’s worth doing before you start anything. Check the boot settings afterwards to make sure it hasn’t changed which of your storage drives the PC boots from.
You may also find your BIOS has a handy auto overclocking function - many of the modern boards will come with such things. They can, however, be a bit hit and miss, but it’s worth giving it a go at first to see what your motherboard can do on its own. If nothing else it might give you a better platform to continue overclocking from manually.
4. Long multiplication
Your processor’s clockspeed is worked out by multiplying the baseclock (BCLK) by the CPU multiplier. The BCLK will likely be set at 100MHz by default, so for a Core i5 6600K, for example, the multiplier will be set at 35 out of the box producing a final clockspeed of 3.5GHz.
Boosting your CPU’s clockspeed then is simply a matter of stepping the processor’s clockspeed multiplier up by one, testing whether the machine still boots and then running a quick Cinebench test to check stability. You will need to set the CPU multiplier/ratio setting to Manual/Sync All Cores and enter the desired number. You should then see a calculation of the final clockspeed somewhere on the page. Then save the settings and restart your machine, booting into Windows.
Once on your Windows desktop start up CPU-Z and Real Temp then run the CPU test in Cinebench to make sure your processor’s operating stably. Keep an eye on CPU-Z to check whether the chip is running at the expected speed and check the processor’s temperature in Real Temp to make sure it’s not running insanely hot.
Then, if everything works as it should, reboot into the BIOS and rinse and repeat until either the machine refuses to boot (why, hello Mrs. Bluescreen of Death, how nice to see you…) or it falls over part way through your stability benchmark.
When that happens simply reboot into your BIOS again to change the settings. Chances are the POST screen will lock when you restart, with a message saying ‘overclocking has failed’ and immediately give you the option to jump into the BIOS screen. From here knock the multiplier down by one, save and reboot testing for stability in Windows.
If you get into a horrible boot cycle where your machine freezes before you can get into your BIOS don’t panic, all is not lost. You may need to delve into your machine and get a look at your motherboard though. You may need to hard reset your motherboard’s BIOS, but the method can differ from manufacturer-to-manufacturer - Google is your friend here. It will either be a little button on the back panel of your board (if you’re lucky) a button on the motherboard inside your case (if you’re not quite so lucky) or a jumper switch you need to short on the PCB itself (if you smashed a mirror over a black cat).
4. Double check
When you’ve reached the limits of what boosting the multiplier can get you then it’s time to make sure your machine is still 100% stable. Prime95 is a great stress-testing tool for CPUs - if your overclock can survive 10 minutes running Prime95 chances are your new clockspeed is pretty damned solid. Boot up both CPU-Z (to check the clockspeed stays constant) and Prime95, selecting the small FFTs when the torture test screen pops up.
Run the torture test for at least 10 minutes and then, when you’re happy with the chip’s stability, you will need to make sure to click the Test tab in the Prime95 window and stop the test manually. Just shutting the window down won’t necessarily do the job.
Now you will have a rock-solid CPU overclock, hopefully at least boosting the minimum frame rates in-game and potentially freeing up a little extra performance from your graphics cards as a whole.
5. There must be more to it than that....
Of course there is if you want to go even further with your expensive silicon. If you want to get elbow deep into CPU overclocking you can start messing around with the voltages and baseclock settings, but that way lies greater long term risk to your hardware and a lot more intricate fiddling in various BIOS settings too. Besides, fiddling with voltages also increases the heat output and may only get you a little higher clockspeed. You can also increase the BCLK of some processors too, but doing that is more prone to failure too.
You can though improve the cooling of your CPU and your PC as a whole which may help net you a higher final clockspeed. If you’re running the same stock cooler which came boxed up with your processor then your chip is likely to be getting more toasty than it needs. A good third-party cooler can be surprisingly cheap and can help improve overclocking scores by a good long way, as well as ensure that an overclocked CPU keeps on trucking without falling over a little while down the line.
Had any luck with overclocking? What's your proudest silicon-based achievement? Let us know in the comments below.