The 3rd Gen Ryzen 3000 CPUs may have won hearts and wallets, and then some but many people including journalists and experts are still confused as to how the power scaling and voltages are regulated in AMD’s new 7nm Zen 2 chips. This is especially true in case of the idle voltages and TDP which reportedly go as low as 5-10W. According to Robert Hallock, Senior-Technical Marketing Manager at AMD Ryzen, the existing monitoring tools like CPU-Z and HWINFO don’t give an accurate reading of the core clocks and voltages. Instead, he recommends using the Ryzen Master app. This is explained as follows:
According to Hallock, the Zen 2 chips use the “Ryzen Balanced Power Plan”. This reduces the wake-up latency, allowing the CPU to respond to requests as fast as 1ms, significantly improving the snappiness and overall performance. In contrast, the Windows’ Balanced Plan takes up to 15ms to respond to requests.
Most voltage monitoring tools will cause the CPU to go from idle to active (if the performance-enhancing plan is active), thereby showing you the boost clock voltages. This is the Observer effect.
CPU-Z does an excellent job of showing you the current/true idle core voltage without observer effect. In my example image, I’ve configured a Ryzen 9 3900X with all the same things we would advise the public to use: Windows 10 May 2019 Update, the latest BIOS for the Crosshair VIII, and chipset driver 1.07.07 (incl. the AMD power plan). Yes, we’re monitoring the behavior of the core, but we can see that idle voltage looks great. The tool is not compelling the firmware to boost when it’s not needed.
Rob Hallock
There’s an additional low-power state called cc6 sleep. In this state, the voltages and frequencies are essentially zero, and it’s not possible to monitor them without waking up the cores and thereby discarding the cc6 power state. Only the latest version of AMD Ryzen Master is able to uniquely monitor the clocks and voltages in this state, and no other tool can do so. So, those of you wanting to check out how power efficient the Ryzen 3000 CPUs really are, you may want to try this out.
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