High Power Consumption of AMD RX6800xt in Idle with Secondary Monitor Connected

[Jaroslav Pulchart]

Yes, I can try two panels of the same model. The results are:
LG 32UL950 + LG 27UL850 => "MCLK constant boost" (issue)
LG 27UL950 + LG 27UL850 => "MCLK is scaling down" (no-issue)

>
> [AMD Official Use Only - AMD Internal Distribution Only]
>
>
> yeah,  there timings look the same, but could you try panels of exactly the same model?
>
>
>
> Humphrey
>
>
>
> ________________________________
> From: Jaroslav Pulchart <jaroslav.pulchart at gmail.com>
> Sent: Tuesday, July 2, 2024 13:59
> To: Feng, Kenneth <Kenneth.Feng at amd.com>
> Cc: Li, Humphrey <Humphrey.Li at amd.com>; Alex Deucher <alexdeucher at gmail.com>; amd-gfx at lists.freedesktop.org <amd-gfx at lists.freedesktop.org>
> Subject: Re: High Power Consumption of AMD RX6800xt in Idle with Secondary Monitor Connected
>
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
>
>
> I see the same modeline setting for both of them, does that mean "same timing" ?
>
> $ xrandr --verbose | grep '*current' -A 2
>   3840x2160 (0x4a) 533.250MHz +HSync -VSync *current +preferred
>         h: width  3840 start 3888 end 3920 total 4000 skew    0 clock 133.31KHz
>         v: height 2160 start 2214 end 2219 total 2222           clock  60.00Hz
> --
>   3840x2160 (0x4a) 533.250MHz +HSync -VSync *current +preferred
>         h: width  3840 start 3888 end 3920 total 4000 skew    0 clock 133.31KHz
>         v: height 2160 start 2214 end 2219 total 2222           clock  60.00Hz
>
>
> >
> > [AMD Official Use Only - AMD Internal Distribution Only]
> >
> > The two high resolution panels have different timings so it's needed to be fixed to high memory clock level.
> > @Li, Humphrey to further comment.
> > Thanks.
> >
> >
> > -----Original Message-----
> > From: Jaroslav Pulchart <jaroslav.pulchart at gmail.com>
> > Sent: Tuesday, July 2, 2024 12:20 PM
> > To: Feng, Kenneth <Kenneth.Feng at amd.com>
> > Cc: Alex Deucher <alexdeucher at gmail.com>; amd-gfx at lists.freedesktop.org
> > Subject: Re: High Power Consumption of AMD RX6800xt in Idle with Secondary Monitor Connected
> >
> > Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> >
> >
> > Hi,
> >
> > Yes, they are 4k monitors. Any reason for such and expected boost for them?
> >
> > BTW: I try to increase blanking periods for both monitors without any change.
> >
> > Jaroslav P.
> >
> > >
> > > [AMD Official Use Only - AMD Internal Distribution Only]
> > >
> > > Hi Jaroslav,
> > > Are both of your monitors 4K resolution?
> > > Then most likely the memory clock is expected to be boosted.
> > > Thanks.
> > >
> > >
> > > -----Original Message-----
> > > From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of
> > > Alex Deucher
> > > Sent: Monday, July 1, 2024 11:07 PM
> > > To: Jaroslav Pulchart <jaroslav.pulchart at gmail.com>
> > > Cc: amd-gfx at lists.freedesktop.org
> > > Subject: Re: High Power Consumption of AMD RX6800xt in Idle with
> > > Secondary Monitor Connected
> > >
> > > Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> > >
> > >
> > > On Mon, Jul 1, 2024 at 3:25 AM Jaroslav Pulchart <jaroslav.pulchart at gmail.com> wrote:
> > > >
> > > > Dear AMD GPU Kernel Maintainers,
> > > >
> > > > I am writing to report an issue with high power consumption of my
> > > > AMD RX6800xt graphics card when a secondary monitor is connected.
> > > >
> > > > Upon investigation, I observed that my desktop computer generates
> > > > more heat while idling. I determined that the high power consumption
> > > > issue arises when I connect a secondary monitor to my AMD RX6800xt
> > > > card, causing it to consume approximately 40W of power in idle state .
> > > >
> > > > I checked the "GFX Clocks and Power:" in
> > > > /sys/kernel/debug/dri/1/amdgpu_pm_info of my RX6800xt during idle,
> > > > and here are the findings:
> > > >
> > > > With the secondary monitor connected memory frequency is up and
> > > > constantly at 1000MHz:
> > > >         1000 MHz (MCLK)
> > > >         3 MHz (SCLK)
> > > >         1825 MHz (PSTATE_SCLK)
> > > >         1000 MHz (PSTATE_MCLK)
> > > >         856 mV (VDDGFX)
> > > >         45.00 W (average SoC)
> > > >
> > > > Single monitor connected:
> > > >         96 MHz (MCLK)
> > > >         0 MHz (SCLK)
> > > >         1825 MHz (PSTATE_SCLK)
> > > >         1000 MHz (PSTATE_MCLK)
> > > >         6 mV (VDDGFX)
> > > >         8.00 W (average SoC)
> > > >
> > > > The significant difference in power consumption between the two
> > > > states indicates a potential issue in power management that needs to
> > > > be addressed. Your assistance in resolving this matter would be
> > > > greatly appreciated.
> > >
> > > It depends on the timing of the monitors.  The memory reclocking can only occur during blanking periods on the monitors.  If the reclocking is done outside of the blanking periods, you will see flickering or artifacts on the display when it happens.  If the blanking periods are too short the driver can only downclock memory when the displays are off.  Adding more monitors makes this harder as you have to take into account the blanking periods on all monitors.  You can try adjusting the modelines used on each display to increase the blanking periods.
> > >
> > > Alex