AMD not only does not leave, but doubles . After having favorably surprised us that the Ryzen series CPUs 5000 presented so far ( Ryzen 9 5950 X, 5900 X, Ryzen 7 5800 X and Ryzen 5 5600 X), the company is ready to relaunch with Precision Boost Overdrive 2 , second generation of the overclocking functionality of Ryzen CPUs that will arrive thanks to new BIOS in distribution in December based on the A GESA 1.1.8.0 on motherboards with series chipset 500 is 400 – some models, such as MSI X 570 Godlike and Gigabyte X 570 Aorus Master, already offer firmware with this functionality.

Prev ision Boost Overdrive 2 (PBO2): what it is and what it does

Precision Boost Overdrive 2 is, as the name implies, an evolution of Precision Boost Overdrive (PBO) , an automatic overclocking feature that the company introduced with Ryzen processors Second generation threadripper and later also offered on Ryzen 600. The first generation of the technology was meant to increase performance with multi-threaded loads , increasing the power supply to the socket and VRM, substantially going to “overwrite” the maximum boost frequency to bring it to a new level.

PBO was therefore not effective on single-thread loads , which is the subject of great attention with CPUs Ryzen 5000 Zen 3 as we have seen in our reviews. Precision Boost Overdrive 2 (PBO2) corrects this behavior, and not only that, because it also introduces undervolt , that is the operation of the CPU with a voltage lower than the standard one.

PBO2 therefore increases the single-thread performance, keeping at the same time the guaranteed improvements in multi-thread and indeed, guaranteeing even more performance in such a scenario. PBO2 is an algorithm that only works on Ryzen CPUs 5000 , extracting even more power from the already excellent single-thread capabilities of these CPUs. For example, as shown in the following graphs, with PBO2 a Ryzen 7 5800 X comes to deliver higher single-thread performance than a Ryzen 9 5900 X in traditional operation.

It is however important to know that like manual overclocking, the performance improvements are variable , because each chip has a different “silicon” quality. Indeed, everything is based on a new automatic technology called “ Curve Optimizer ” which opportunistically adjusts the voltage based on the operating conditions , operating an undervolt based on the capacity of the single chip and the temperature (linked , obviously, to the cooling system).

As we have seen over the years, there are scenarios and situations in which the reduction of operating voltage compared to the standard allows the CPU to work without problems, and indeed due to the lower temperatures of guarantee greater performance, as it is capable of operating at a higher frequency. And this is exactly what Precision Boost Overdrive 2 and more specifically Curve Optimizer does.

Compared to the previous generation that intervened on individual milliwatts, the renewed mechanism works in blocks (AMD calls them count) of approximately 3mV-5mW each. This interval, according to the company, leads to have a lower undervolt when the load is higher, and a higher voltage reduction when the load is lower.

Users have control over the “number of blocks”, with the possibility of set up to 30, therefore an undervolt interval of 90 – 150 mV . Furthermore, Curve Optimizer can be used on both a single core and all cores of the CCX . “The algorithm is adaptive, it knows when to remove voltage and when not to”, explained AMD, reminding us that all the variables involved are monitored once every millisecond thanks to the sensors that communicate via Infinity Fabric Fast Interconnect.

PBO2 with Curve Optimizer will also arrive in Ryzen Master early next year , but there is one though: activate it invalidates the warranty , but the same can be said for overclocking in general and for the previous generation PBO. However, it must be considered that since it is an automatic function, it is difficult to set voltages or other parameters that are dangerous for the life of the CPU.