5800X3D Idle Power Consumption

Many users tend to observe higher idle power consumption than in other Ryzen processors, which usually falls between 28-30W. This is may be worrying especially to those who consider energy efficiency to be of paramount importance.

Why Does the Ryzen 5800X3D Have Higher Idle Power?
The higher idle power in the Ryzen 5800X3D can be attributed to several unique factors:

3D V-Cache Power Draw: The innovative solution of 3D V-Cache is also aimed at enhancing the gaming capabilities through the enlargement of L3 cache size with the assistance of additional layers. Nevertheless, this cache does not go into low power modes during idle time because of the TSVs communication. Therefore, the cache alone can consume an extra 7-10W, when the cores themselves are at below 2W activity levels.

Motherboard and BIOS Configuration: The power consumption of a computer may also depend on the BIOS version, power plan and other settings that is inherent in the motherboard. Some people found out that after updating the BIOS or changing some settings, the idle power consumption can be lowered.

Windows Power Management: The default power plan settings of Windows may still not deliver maximum idling efficiency for this specific CPU. As one can read, some users have discovered that the Balanced or the High Performance schemes maintain the clock speeds high continuously, which leads to the increased idle power consumption.

How to Reduce Idle Power Consumption
To achieve better efficiency, consider the following tweaks and adjustments:

Enable ECO Mode:

AMD’s ECO Mode can either be enabled through the BIOS or through the AMD Ryzen Master. It minimizes power constraints, which in turn may help lower the idle power consumption by as much as 5-10W without a severe hit on performance. This is especially valuable if you don’t always stress the CPU to the max of its capability.
Adjust Power Plan Settings:

Try using the Energy Saver option or develop a new power scheme. Minimum Processor State should be set to 0-5% while the Maximum Processor State should be set to 100%.
This adjustment helps the CPU to reduce the bus operating frequency during time when it is not busy. Some users said that with this setup, they can see idle clock speeds of 1.0-1.7 GHz which lowers power consumption.
Undervolt Using PBO2 Tuner:

It is necessary to mention that the Precision Boost Overdrive 2 (PBO2) Tuner tool enables users choose negative voltage offsets (undervolting). The undervolt of 30mV is possible to apply to decrease power consumption without affecting battery stability.
They are confused when 30 in PBO2 means it is not 30mV but may be more like 90mV or even more due to the BIOS setting. It is suggested to conduct a slow and careful test and then to monitor its effects.
Monitor SOC Voltage:

The SOC voltage can be reduced to reduce idle power as well. Some users recommend setting the SOC voltage manually to 1.0-1.05V, this reduces idle package power to a range of about 18-22 watts. But do so in a way that your system maintains stability with this kind of setting.
Disable Unnecessary Background Processes:

Other monitoring applications that can be useful are MSI Afterburner, HWInfo and probably any other similar programs. Always look out for any running background application that may be making the CPU busy. When in MSI Afterburner, look for the “i” (information) icon to find out if there is any 3D process running that would interfere with the CPU’s ability to enter low-power states.

Real User Experiences
I’ve gathered insights from various forums and my own experience with the Ryzen 5800X3D:

User Report:

One user had a B450 Tomahawk motherboard and he discovered that when he turned on the ECO Mode and reduced the SOC voltage to 1.05V, the idle power consumption was stabilized at 20-22W. However, they pointed out that undervolting alone would not have such effect without making more power plan tweaks.
Another Experience:

A user wrote that after installing AMD Chipset Drivers the Cool & Quiet did not work properly, and the idle clock speeds were high (4 GHz). When the chipset drivers were uninstalled, the feature became operational and the idle clocks reduced to 1.7 GHz, thus improving power consumption.
Windows 11 vs Windows 10:

I asked some users about this and many of them said that on Windows 10 the idle power was always below Windows 11 with having the same settings. This implies that some of the power management features may operate uniquely under the two operating systems.
My Personal Recommendation
From my own experience with the 5800X3D, I found the following combination to be most effective:

There is also an option in the BIOS that will engage ECO Mode for a power decrease.
Turn on energy saver power plan and set up the Minimum Processor State to 0%.
Use PBO2 Tuner to set an undervolt of between 20 and 30 and then use HWInfo to observe the outcome.
Programmatically reduce the SOC voltage to around 1.05 V because that offered an optimal stability and low power saving.