AMD Graphics Driver In Linux 6.5 Improves Power Management, Adds CP Shadow Buffer

[phoronix]

Phoronix: AMD Graphics Driver In Linux 6.5 Improves Power Management, Adds CP Shadow Buffer

On Friday a big set of patches affecting the AMDGPU/Radeon/AMDKFD kernel drivers were submitted for DRM-Next to queue until the Linux 6.5 kernel merge window opens in the coming weeks. A lot of new feature code is part of this pull for benefiting new hardware, continuing to refine AMD GPU power management under Linux, and more...

https://www.phoronix.com/news/AMDGPU-Linux-6.5-Improvements

[Desti]

Will memory clock down now work with higher monitor refresh rates and multi monitor?

[Laughing1]

Will memory clock down now work with higher monitor refresh rates and multi monitor?

Yes that would be nice to have, now that HDR is coming to Linux in the not so far future.

[verres]

I want a proper GPU mem downclock on multi monitor setting. It isn't fun with 100W power usage in 2D desktop.

[caligula]

So, do these only affect the users of the most recent generations? I think there are some power management improvements left for the older gens as well (e.g. Polaris, first gens of RDNA).

[Grinness]

I want a proper GPU mem downclock on multi monitor setting. It isn't fun with 100W power usage in 2D desktop.

On what gpu do you experience 100W consumption?
On RDNA2, 2 monitors (2* 1440p) I have between 7 and 11W (idle - all open stack):

> sensors
amdgpu-pci-0d00
Adapter: PCI adapter
vddgfx:        6.00 mV
fan1:           0 RPM  (min =    0 RPM, max = 3300 RPM)
edge:         +57.0°C  (crit = +100.0°C, hyst = -273.1°C)
                       (emerg = +105.0°C)
junction:     +60.0°C  (crit = +110.0°C, hyst = -273.1°C)
                       (emerg = +115.0°C)
mem:          +56.0°C  (crit = +100.0°C, hyst = -273.1°C)
                       (emerg = +105.0°C)
PPT:           7.00 W  (cap = 203.00 W)​

Similar story on Polaris (2* 1080p)

[bridgman]

So, do these only affect the users of the most recent generations? I think there are some power management improvements left for the older gens as well (e.g. Polaris, first gens of RDNA).

On what gpu do you experience 100W consumption?
On RDNA2, 2 monitors (2* 1440p) I have between 7 and 11W (idle - all open stack):

Guessing that you have two identical monitors while caligula has two different monitors. Normally if the two displays have the same timing info then we will lock them together and don't have problems finding a blanking window to downclock memory.

[Grinness]

Guessing that you have two identical monitors while caligula has two different monitors. Normally if the two displays have the same timing info then we will lock them together and don't have problems finding a blanking window to downclock memory.

No I do not have same monitors, I have 1 monitor (DP) and 1 TV (HDMI), both at 1440p and 60Hz (this is for RDNA2)
1 monitor and 1 TV, both 1080p 60Hz on Polaris

On RDNA2, setting monitor 1440p 140Hz and TV 1440p 60Hz, i get 34W idle -- not 100W

EDIT: all above on Arch, latest zen kernel, mesa, KDE, Wayland

[SearingHeat]

Two identical 4K@60Hz (DP) displays, one in portrait configuration. Mutter, wayland, mesa-git, kernel 6.4.0-0.rc4 on a 7900 XTX, completely idle system:

amdgpu-pci-0300
Adapter: PCI adapter
vddgfx: 174.00 mV
fan1: 0 RPM (min = 0 RPM, max = 3200 RPM)
edge: +46.0°C (crit = +100.0°C, hyst = -273.1°C)
(emerg = +105.0°C)
junction: +50.0°C (crit = +110.0°C, hyst = -273.1°C)
(emerg = +115.0°C)
mem: +63.0°C (crit = +108.0°C, hyst = -273.1°C)
(emerg = +113.0°C)
PPT: 43.00 W (cap = 291.00 W)​

[verres]

On what gpu do you experience 100W consumption?
On RDNA2, 2 monitors (2* 1440p) I have between 7 and 11W (idle - all open stack):

On RDNA3 7900XTX. When single monitor is connected then reported GPU power usage is around 25W (mem clock is below 100MHz). When two monitors are connected then reported GPU power is around 96W (mem clock 1.2GHz). This also depends on resolution on my second monitor:
1. 4K + 1920x1200 = 1.2GHz
2. 4K + 1680x1050 = 460Mhz
3. 4K + 1280x800 = below 100Mhz

When second monitor is connected to the integrated graphics (7800X3D) then GPU power usage is OK, but then I am experiencing some flickering.