If there's anything to know about PC enthusiasts, it's that we love large numbers: high voltage, high clock speeds, and high framerates. GPU overclocking was chief among the tweaks that many users would first turn to in order to squeeze as much performance out of their shiny new card as possible, but things have changed.

Modern GPUs from the last couple of generations already push themselves quite close to the edge out of the box. Of course, you can always push components well past their conventional limits with things like liquid nitrogen, but for everyday use, most cards are pretty good at running as fast as they're reasonably capable of. Boost algorithms are good at scaling voltage and frequency based on workload, and as a result, owners of newer cards should attempt to undervolt before they ever touch an overclock.

Overclocking isn't what it used to be

Cards simply can't be pushed as far as they used to go

Overclocking a GPU used to come with significant performance benefits. A few millivolts here, some boosted core clocks there, and you could easily walk away with a genuine 10% gain in real-world performance. Now, boost clocks have largely bridged that gap.

Any modern card will simply boost to a reasonable clock speed while keeping thermals and power draw under control. Pushing them any harder with higher voltages and clock speeds generates exponentially more heat for only a few percent gain. Take the RX 9070 XT for example. Through the Adrenalin software, it's not even possible to add a positive voltage offset. The only controls given to you are adding a negative voltage offset, power limit, and setting the max frequency offset. Overclocking is basically nonexistent beyond what is given to you out of the box, and it's not like AMD is pulling punches with these cards.

Even if you could add voltage along with increasing the max frequency offset, like you would in a normal manual overclock, all you would cause is more throttling. These modern cards will hit their power or temperature limits far before you reach any significant performance bump.

Undervolting is a much better way to tune your GPU

Less power is actually better

Undervolting is the opposite of overclocking: you’re giving your GPU less power instead of more. That might sound counterintuitive, but the results can be quite surprising, if it's done the right way. Every GPU has a voltage curve that determines how much juice it needs to hit a certain clock speed. By editing that curve, you can tell your GPU to hit the same frequencies with less voltage.

The effects can be pretty dramatic. Lower power draw, lower heat, quieter operation, and you can often see higher sustained boost clocks because the GPU stays cooler for longer. It's also much more straightforward to do.

Undervolting a GPU is quite simple

Takes less trial and error than dialing in an overclock

On my RX 9070 XT, undervolting can be done through the aforementioned AMD Adrenalin software. Starting with a modest undervolt like -40 mV is a good place to start, as most of these cards can handle at least that. It's important to note that not all cards can take to an undervolt as well as another that has an identical GPU. If someone achieves a stable, -100 mV undervolt with your model of GPU, don't expect the same thing out of your card. Even if it's a more premium GPU that likely has binned silicon (meaning they've selected only the highest quality chips for a certain model of card), it doesn't mean that all cards can achieve the same level of undervolt.

The steps from here are largely the same as overclocking. Set the voltage offset, and test for stability, decreasing a little more each time. You can then begin to play with the power limit slider. Higher power limit means your card will suck back more power, boost higher, and create a much more significant amount of heat. For my card, if I crank the undervolt down to -100 mV and run FurMark with an added 10% to the power limit, my temps jump up much faster, but I do see a significant bump in performance. My clock speeds jump up about 300 MHz, depending on the workload.

Decreasing the power limit does decrease my performance, but I can cut 30–50 W off of the total power draw, and temps drop up to 5 degrees or more, even with the beefy cooler on my Sapphire Nitro+ card. It should also be noted that this -100 mV offset, while stable in FurMark, might not be stable under a real-world workload, like a graphically intensive game. Finding what is stable in those specific cases will take some more trial and error.

An undervolt is the new overclock

Overclocking was effective until cards started being shipped with highly tuned boost algorithms and high clocks out of the box. Now, it's all about increasing efficiency by undervolting, and a knock-on effect of that is higher clock speeds, lower temperatures, and in turn, the same (or even better) performance.