Investigating the Cause and Effect of an AMD Zen Energy Management Anomaly

Publikation: Sonstige VeröffentlichungSonstigesBeigetragenBegutachtung


This paper discusses an architectural anomaly observed on server processors of the AMD Zen microarchitecture: At a specific operating point, increasing the number of active cores reduces system power consumption while increasing performance more than proportionally to the additional cores. The occurrence of the anomaly is rooted in the hardware control loop for energy management and software-independent. Experiments show a connection to the AMD turbo frequency feature Max Core Boost Frequency (MCBF). In less efficient configurations, this feature could be employed from a processor's perspective, even though it is not necessarily used on any core. Voltage measurements indicate that the availability of MCBF leads to a higher voltage from mainboard voltage regulators, subsequently raising power consumption unnecessarily.


PublikationsstatusVeröffentlicht - 2021
No renderer: customAssociatesEventsRenderPortal,dk.atira.pure.api.shared.model.researchoutput.OtherContribution

Externe IDs

Scopus 85104980257



  • AMD ZenEnergy