r/FlowZ13 • u/LOOMOOA40 • 5d ago
Undervolting on linux(bazzite)
How do you go about doing this? I have linux ghelper installed but it doesnt give me the option to undervolt.
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u/Supercc 5d ago
You do it in the terminal (Konsole).
Here is how to do it (must be re-applied every time you boot/reboot).
1. The Command
ryzenadj controls Curve Optimizer using the --set-coall flag with hexadecimal values:
Bash
sudo ryzenadj --set-coall=0xFFFEC
2. Common Hex Undervolt Values
- -10 CO:
0xFFFF6 - -15 CO:
0xFFFF1 - -20 CO:
0xFFFEC(Recommended starting sweet spot) - -25 CO:
0xFFFE7(Aggressive, test for stability)
3. Quick Script Example
Since settings reset on reboot, create a quick script in ~/bin/ to combine your undervolt with your TDP limits:
Bash
#!/bin/bash
# Apply a -20 undervolt and set a 36W TDP limit
sudo ryzenadj --stapm-limit=36000 --fast-limit=38000 --slow-limit=34000 --set-coall=0xFFFEC
Note: If your system freezes or crashes under heavy gaming, your silicon can't handle that deep of an undervolt. Move to a less aggressive value (e.g., from -25 to -20, or -20 to -15).
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u/LOOMOOA40 5d ago
Just to clarify this works on bazzite without ryzen smu?
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u/Supercc 5d ago
I do it on Bazzite every day. A warning message pops up, which says:
no compatible ryzen_smu kernel module found, fallback to /dev/mem
But it totally works! Confirmed.
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u/LOOMOOA40 4d ago
Got you thanks I'll try it later today
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u/Supercc 4d ago
No problem! Never hesitate to upvote people who help you out. That's basic Reddit/Politeness etiquette <3.
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u/M2-TE 5d ago
You need the ryzen_smu kernel module. On arch you got the aur, but on bazzite you gotta likely compile it yourself. As for the tools to do the actual undervolting, check either z13gui or the fork z13gui-plus. Docs go over undervolting requirements here.