Zen presented AMD with a number of new challenges in the area of power largely due to their decision to cover the entire spectrum of systems from ultra-low power to high performance. Previously AMD handled this by designing two independent architectures (i.e., {{\\|Excavator}} and {{\\|Puma}}). In Zen, SoC voltage coming from the Voltage Regulator Module (VRM) is fed to the RVDD, a package metal plane that distributes the highest VID request from all cores. In Zen, each core has a digital [[LDO regulator]] (low-dropout) and a [[digital frequency synthesizer]] (DFS) to vary frequency and voltage across power states on individual core basis. The LDO regulates RVDD for each power domain and create an optimal VDD per core using a system of sensors they've embedded across the entire chip; this is in addition to other properties such as countermeasures against droop. This is in contrast to some alternative solutions by [[Intel]] which attempted to integrated the voltage regulator (FIVR) on die in {{intel|Haswell|l=arch}} (and consequently removing it in {{intel|Skylake|l=arch}} due to a number of thermal restrictions it created). Zen's new voltage control is an attempt at a much finer power tuning on a per core level based on a collection of information it has on that core and overall chip.