How To How to Undervolt the Ryzen 7 5800X3D - Without Manually Changing BIOS Settings

[kenstj]

I came across this life changing process to skirt the need for you to manually change BIOS settings in order to undervolt the 5800X3D when no such options exist in your particular BIOS. It is for newbies / beginners / advanced users/ and the overclocking clueless like myself. Just follow the instructions and It simply works.
IMPORTANT NOTE: There is one missing clarification in the process steps that you will need to save you grief:
In the step entitled "Create the Trigger for Wakeup" in order to get the option for setting up a New Event Filter, in the "Begin the task" dropdown you must select an event type of "On An Event". Otherwise you'll not see this option to create a filter.
https://github.com/PrimeO7/How-to-undervolt-AMD-RYZEN-5800X3D-Guide-with-PBO2-Tuner

 

[Order 66]

If you haven’t already, download Ryzen master and run the curve optimizer and that will undervolt it automatically.

 

[kenstj]

If you haven’t already, download Ryzen master and run the curve optimizer and that will undervolt it automatically.

Thanks for adding to the topic! The RM won't do anything with the 5800X3D because it's locked down. Also, the Basic view has been depreciated and no longer there which is - in my opinion - a real loss.

 

[USAFRet]

You might want to put a description of why a person might want to undervolt.

 

[Colif]

The reason they locked the CPU down is because the 96mb of lvl 3 cache has to run at a certain speed or you get problems.

One MSI motherboard adds the ability to boost these CPU but you don't get a lot of benefit from doing so.

 

[kenstj]

You might want to put a description of why a person might want to undervolt.

Recently added was an RTX 4070 to replace an older card. As I noted in a previous post elsewhere, under load doing FFMPEG processes and equivalent Stable Diffusion workflows the CPU core(s) temps would quickly rise to 90+ degrees C and power dissipation would go beyond 125 watts sometimes spiking to 135 watts. Although the dissipation technically was technically still within spec according to AMD, long term effects on lifetime are still concerning to me as are the over temps for the same reason.
After going through the usual cast of suspects centering around coolers, cooling, and bottlenecks I turned to under voltage adjustments. BTW - Ryzen Master is no help with the 5800 in this regard as it is after all an AMD utility which honors AMD restrictions and locks out adjustments typically available with other processors.
Adjusting the core voltages lower had a major effect on both lowering temps below suggested Tj (90C to <79C) and reducing dissipation below suggested TDP (105W to < 75W) while simultaneously having no discernable effect on the boost frequency (4450 Mhz in my system).
The GitHub link I posted provides a straight forward process to accomplish this. In this process the acceptable range of possible change is represented by a relative curve offset number from 0 to 30. For my personal needs using 15 was enough to result in the changes noted above under maximum load for the applications I was using. The implication here is that you could even go higher and produce even more dramatic changes. However, you'd have to do stress tests (i.e. Cinebench 23 etc.) as you change it and watch for <boost> performance degradation. Hope this helps someone!

 

[kenstj]

The reason they locked the CPU down is because the 96mb of lvl 3 cache has to run at a certain speed or you get problems.

One MSI motherboard adds the ability to boost these CPU but you don't get a lot of benefit from doing so.

True enough re locking. See my reply re reasons for an undervoltage approach.