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Journeyman III

Undervolting for laptop AMD cpu and gpu.

Greetings good people of Bharata. Recently I have purchased AMD Advantage edition laptop g15, with Ryzen 9 5900hx and Radeon RX 6800M, and sadly there is no software whatsoever to do undervolting. While Armoury crate options to lower APU sPPT is something general, i'm looking for ways to do undervolting. I also know of Ryzen Controller, but when activating some options there, it actually lowers general W input while in game or in benchmark test, beside cinebench, I think only Temperature option is good to go, which is good to have of course, but is nothing like to tinker with undervolting.

Question is, why AMD is not giving this tools ? 

4 Replies

Actually, I have a question for you.

What is the BIOS like?

The Ryzen 9 5900Hx comes with a configurable TDP  35-54W.   With a default TDP of 45+W.  Does your BIOS give you options to configure this?

If you have access to PBO then you should be able to set Thermal Throttle Limit, PPT, TDV and EDC.

There are always the power savings plans in Windows.


No, BIOS is very basic no such options there. The TDP is configured with Armoury slider, also with Ryzen Controller. Ryzen controller might be giving incompatibility issues with Armoury, or itself, it will lock both GPU and CPU to almost 300mhz lock speed, if any option other than CPU temp is used, so I cant really control TDP of boots and boost duration. I have put my APU sPPT, CPU W limit to 20, however I think boost allowed W does allow this to override it, because its impossible that with limit of 20W, while in Games, temps jump as high as 85 degrees on full fan speed.

I'm not sure if under certain demand, Armoury settings are just being ignored, or something like that. I see no need to tweak RX 6800M, and temps are fine, but CPU temp jumps are not very linear, and sometime it will start boosting for no apparent reason. I am not professional at this, but would like to learn what I can do to control the behavior. 


You are playing a particularly dangerous game, trying to underclock a laptop.

Have you considered that if you take a setting too far, there is (probably) no External Clear CMOS button?

There might not be a clear CMOS header in the case either.   Even if there were a internal header, or if you try to accomplish the same by removing an internal coin cell battery, opening the case might be really difficult.

There  probably isn't any external button to initiate a bios flash back.

For all the reasons that I stated above, I would back off on this desire.

Maybe you can try it out on a cheap desktop first.

clear CMOS  press 30 seconds power button.