AMD Ryzen 5000 CPUs Will Soon Get Adaptive Undervolting

AMD has announced that it will add a new feature to its Ryzen 5000 CPUs this coming December. The company expects motherboard manufacturers to begin delivering UEFI updates with support for a new features: Precision Boost Overdrive 2.

Precision Boost Overdrive 2 will be introduced with Agesa 1.1.8.0 on 400-series and 500-series motherboards, but the feature will only be supported on Ryzen 5000 processors. PBO2 uses a new tool, dubbed the Curve Optimization tool, to undervolt the CPU, thereby freeing up additional frequency headroom and offering longer boost duration.

The idea here is this: CPUs have set voltages that they operate at when clocked at a given frequency. Sometimes, with modern chips, a particularly good CPU can run at less voltage than is technically required for that frequency. Manufacturers like AMD and Intel have gotten better at soaking up the headroom left over in silicon on a per-chip basis, but PBO2 will allow end users to customize things a little more tightly if they want to squeeze out every last ounce of performance — provided, of course, that you are willing to void your warranty.

End users will have the ability to define how much they want to undervolt the chip, with undervolting adjusted in “counts” rather than raw millivolts. AMD claims that its algorithm can achieve superior performance to the old method of adjusting voltage because it will impact single-threaded and multi-threaded performance, though the expected gains of multi-threaded are much larger. AMD projects up to 2 percent improved performance in single-threaded workloads and up to 10 percent in multi-threaded.

A few other tidbits: The 5900X may be the best target for this technology, based on AMD’s comments that it works best with multiple CCDs and fewer cores per CCD, making that chip the sweet spot for the technology. The tech will be available by default in processors going forward, but it can’t be transferred back to the Ryzen 3000 family due to some non-compatible engineering optimizations required for the 5000 series. Initially, PBO2 will be a feature that you turn on and adjust in UEFI, but AMD plans to add it directly to Ryzen Master next year.

We recommend that end-users approach all overclocking with caution, especially if you aren’t running better than stock cooling. With that said, AMD is clearly trying to find ways to make the performance that was once only available to determined overclockers more easily accessible to regular folks. Undervolting your CPU does not run the same risk of damaging the core that overvolting does, though your CPU may still be unstable at the higher targeted frequencies. Keep in mind that any additional frequency you unlock may only boost performance in certain workloads depending on the characteristics of how the CPU boosts — this isn’t the same as just raising the CPU’s base clock and running at higher frequencies.

Look for Agesa 1.1.8.0 to drop in December. The “up to” numbers AMD claims should, as always, be treated with a grain of salt. Gains may be smaller or nonexistent depending on various factors, including the capabilities of your specific CPU and underlying cooling solution.