AMDGPU Linux Driver No Longer Lets You Have Unlimited Control To Lower Your Power Limit

[phoronix]

Phoronix: AMDGPU Linux Driver No Longer Lets You Have Unlimited Control To Lower Your Power Limit

The AMDGPU Linux driver up until the recent Linux 6.7 kernel release has let you lower the power limit of your graphics card with, well, no limits... This has allowed AMD Radeon Linux users to limit their GPU power draw when desiring for power/efficiency reasons. But since Linux 6.7 they've begun enforcing a lower-power limit set by the respective graphics card BIOS. Users petitioned to have this change reverted but in the name of safety this lower-limit enforcement will stand...

https://www.phoronix.com/news/AMDGPU-Lower-Power-Limit

[ms178]

One patch more to maintain for custom Kernel builds.

[V1tol]

Didn't even notice with my -100mV. Looks like it is considered to be conservative enough.

[Eirikr1848]

Next month on CachyOS: POWER LIMITS REMOVED FOR 6.8

[varikonniemi]

What the f is going on here? At least i would expect an explanation how this would damage the card? Only thing i could think of is it would damage their customer service if someone forgot they set it too low... WTF is this in Linux land. "just make it like windows" ... ????

[aufkrawall]

What the f is going on here?

Driver is now adhering power limit minimum which afair is also defined in vbios. But the main issue is that RDNA3 cards/vbioses simply allow far less power limit reduction vs. older card gens. It is a general tendency of AMD totally screwing up user control over hardware more and more with each new hardware generation.

It was a walk in the park to undervolt RDNA1 by adjusting only the second half of the curve, then RDNA2 introduced the idiotic offset to the whole clock/voltage curve with random instability after many hours of usage and RDNA3 finally even ignores higher clocks configured after a threshold like ~2.7GHz + new power constraints. AMD is basically just lying to users by pretending to offer control via Wattman/overdrive which their idiotic hardware/clock control and telemetry simply doesn't allow (anymore).

[hartree]

Isn't setting a lower power cap equivalent to setting a lower maximum gpu clock?

[dp_alvarez]

This is sad, but expected given recent AMD moves.
In particular the requirement for signed messages to be passed to the PSP in order to control CPU power parameters. Plus the bios-loaded binary blob that enforces power profiles regardless of the OS choices.

It is a very clear strategy of artificial segmentation. You take away users control over that part of the hardware, then you can upcharge customers that want any specific power-related behavior.
Hooray for the software toggle of better battery life vs greater performance being replaced by the convenience of buying another, more expensive, model!

[andyprough]

Because "safety".

"You'll shoot your eye out kid"

[kiffmet]

AMD locking down the hardware more and more sucks. Let experienced users override certain limits! The rest of the users is fine with the default ranges provided. What's being done here is kinda schizophrenic, given that the 7900GRE turned out to be too locked down (AMD called it a "driver bug" - I call it market segmentation and watering down the meaning of "ownership", followed by too many people publicly complaining) and now gets some restrictions loosened.

Tunability and users being able to get the most out of their silicon used to be a main staple of Radeon GPUs. Shame on you, AMD. Getting rid off that practice is scummy and harms the "value" proposition of your GPUs in the current market with overinflated prices further.