LOWER YOUR TEMPS & SAVE MONEY! A Beginners Guide to Undervolting
What if I told you that you could lower your temperatures, save money on your electric bill, and keep getting the same performance? Let me introduce you to the wonderful world of undervolting. Undervolting is pretty simple, you reduce the amount of power your components are using, so they run cooler. The reason it works is pretty simple too – your chips aren’t evenly efficient. They don’t run 1:1 with 1% more power adding 1% more performance, it’s a curve.
Take this Techpowerup article where they tested Intel’s 12900K at various power levels, at the full 241W max boost power level it runs rather well as you’d expect. But, at the much lower 125W base TDP – that’s 48% less power than full boost – it only drops 14% of the performance. You can HALF the power consumption and only lose a seventh of the performance, that’s massive. Let me show you that as a hypothetical graph, if the full 241W boost offers 100% performance, and just 125W runs at 86%, let’s say you are running at stock which is about here. You can drop the power by 25W and not drop even 5% of your CPU performance! That’s frankly incredible, and 25W is no mean feat for cooling either. That could EASILY be the difference between running at 100% fan speed at 100°c on these chips, to comfortably running at more like 70-80°c at more like 75% fan speed, plus assuming you game for an average of 10 hours a week and pay 27p per kilowatt hour, you’d be saving around £3.50 a year JUST FROM YOUR CPU!
So, how do you undervolt your kit? Well, if you have an AMD GPU, it is stupidly easy. Open their GPU driver, head to the Performance tab, then Tuning, click “Undervolt GPU”, let it do its thing and boom, undervolted GPU. Same performance, lower power, lower temps, less noise. Hell you can even get MORE performance thanks to a better thermal headroom. For AMD’s CPUs, sadly it isn’t quite as simple, but it’s still really easy. Download and install AMD’s Ryzen Master software, launch the advanced view, then pick a profile on the top left, like gamer, creator or one of the custom profiles. Set it to Precision Boost Overdrive, then set the package power target or PPT to lower than your stock level – I’ll put them up on the screen so you can reference them yourself, but in general for the 6 core parts you’ll want to set this to 70W or lower, and for 8 core and up 130W or lower is for you.
Technically speaking, by lowering the package power target, you aren’t actually undervolting your CPU there, you are just limiting its power consumption. It still has pretty much the same effect though, so at least for AMD that’s where I’ll leave it.
On NVIDIA GPUs, sadly NVIDIA doesn’t provide any overclocking tools themselves, but there are plenty of aftermarket options you can use instead. In fact, if you bought an AIB – add-in board partner – card, chances are that manufacturer made their own software so you can do just that. Still, MSI afterburner is arguably the most common, and works with most GPUs, so you’ll want to start there. You’ll also need a stress test tool, something like Unigine Heaven works really well for this. You’ll want to fire up heaven on stock settings, and let your GPU get up to temperature. Once it’s stable, check afterburner for what clock speed your GPU is running at. You can also open the curve editor with CTRL + F. There you should see what voltage corresponds to what frequency on your card. Your goal is to lower the voltage even slightly while still keeping your card stable and decently performant.
This process is specific to your card, and isn’t an exact science, more trial and error than anything, so you can’t just copy what I’m showing here. But the theory is simple enough – let’s say your card is running at 1900MHz and needs 1000mV to do that, you might want to tweak the core clocks to run at more like 1850MHz and 950mV instead. In theory the sweet spot for the RTX 30 series cards is around 1800MHz anyway, so if you can lower the clock speeds to that you should net a decent temperature and power savings. Make the adjustment in the main window, then re-run heaven to make sure the card is still stable and running well. Once you are happy with it, you’ll want to go back into the curve editor and drag all the points past your target voltage down to make sure the card doesn’t exceed your targets.
Finally, when it comes to Intel CPUs, the easiest way to do that is through Intel XTU. Much like AMD’s Ryzen Master tool, it’s a Windows based program that means you don’t have to dive into the BIOS every time you want to make a change. Much like Ryzen, you can take the easier route by just changing the power limits and turbo behaviours – under the “Advanced Tuning” tab, under “Core” you can change the Turbo Boost Power Max value to lower than stock – on the right you’ll see a list of “default” settings, with the turbo boost short power max being your PL2 and turbo boost power max being your PL1. You can lower both of these, although the long boost is the one to keep an eye on first.
If you want to go down the more advanced route, the core voltage offset is what you’ll want to adjust. Happily XTU has a stress test built in, so it’s best to run that first to get an idea of what your chip does, then come back and start decreasing the core voltage offset and re-testing. You can basically keep going until your system becomes unstable, then crank it back up a notch or two.
So, that’s a quick look at undervolting. It’s a great tool to have available when you want to keep things cool – especially in hot weather like now – while still getting great performance.
