Control of GPU powermanagment

[kas1e]

@All

Find out later that if i put into x5000 under Linux (flenix) 1950 or much better ones hd6970 - the speed in my tests remains the same! No fps increase at all. And, from the noise i heard from the GPU fan, it is in no way changing.

I think that problem is that PowerManagment sitting in some "auto" mode, and didn't rise resources where it needs it.

So, if anyone knows, how to control power management on the Linux side? All i can find at moment is that on some linuxes, you can change

/sys/class/drm/card0/device/power_dpm_force_perfomance_level

And by default, we have it in "auto", but setting it to "low" or to "high" changes nothing, and i didn't hear that the GPU fan is starting to move faster.

I also found that:

/sys/class/drm/card0/device/power_dpm_state

It has options like "batter", "balanced" and "performance". By default, it is "balanced" and setting it to "performance" also changes nothing, speed of the GPU fan didn't changes, and FPS in test cases remain the same.

Any ideas on how to control power management manually? Just want to be sure on what mode i am. As it gives me the same results in my test cases on both x1950pro and on hd6970, my bet is that at least in the case with hd6970 resources didn't rise up automatically when i needed them.

[xeno74]

@All

Find out later that if i put into x5000 under Linux (flenix) 1950 or much better ones hd6970 - the speed in my tests remains the same! No fps increase at all.

There are big differences: DOOM3 time demo results

I never setup the power management.

- Christian

[kas1e]

@xeno74

There are big differences: DOOM3 time demo results

But not in glxgears for example, right ?

I think we have there the same issue we had before on amigaos4 when there wasn't power management software: by default power management is in "auto" state, but for some games/apps it didn't raise power resources dunno why. We think before it was because of due DMA, but Linux seems to use DMA, so seems it wasn't that.

For Doom3 resources probably raises up, and so fps differences is here (i will check that myself later on my x5000/020, maybe i have some wrong setup, dunno).

Do you know who made the Flenix x5000 distro? I mean with who i can talk so to know more about how x5000 Linux gfx drivers work, and how to control power management manually?

[xeno74]

Do you know who made the Flenix x5000 distro?

fienixppc.blogspot.com

You can directly contact Casey (caseycullen) here.

If you need more technical information about the graphics card drivers then you can ask the developers on the following mailing list.

Link: DRI-DEVEL Mailing list

[caseycullen]

Do you know who made the Flenix x5000 distro? I mean with who i can talk so to know more about how x5000 Linux gfx drivers work, and how to control power management manually?

Fienix uses the standard Mesa drivers and Mesa 3D Library. I'd suggest reading https://www.x.org/wiki/RadeonFeature/; specifically the "KMS Power Management Options" section. However, I don't think power management is causing the concerns you have. By default, the GPU is operated in its default state at its default clock and is not subject to power management restrictions. That said, I haven't experimented much with power management options, so if you discover anything please let us know.

Unfortunately, the state of the drivers for PowerPC leaves considerable room for improvement. For example, regardless of the GPU you have, PowerPC drivers are restricted to OpenGL 3.1 (or earlier for older cards).

-Casey

[xeno74]

Code: Select all

setenv bootargs root=/dev/sda4 radeon.dpm=1

1 "dynpm"
2 "profile"
3 "dpm"
You can select the methods via sysfs. Echo "dynpm" or "profile" to /sys/class/drm/card0/device/power_method. "dpm" support, must be selected at boot (via radeon.dpm=1).

[kas1e]

@caseyculen

The problem which i find now is that swapping of Radeon1950PRO to RadeonHD6970 didn't change a single FPS in some of my test cases (and also in GLXgears too). But Xeno says that for him in doom3 he has speed increase for sure. What it can mean is that for some "small examples" power management just didn't raise resources (so we can't see the full speed of the gfx card in some tests). Why i am so sure about that because we have had the same problem on AmigaOS4 before: i installed Radeon RX instead of RadeonHD and things start to be even worse. And in end, we find out that this is power management was on "base" and didn't raise resources (dunno why maybe no proper DMA or something). And this very much familiar with what we have.

Now what we need to be 100% sure that is to be able to control power management manually as we can now on AmigaOS4 via some prefs app. Need to find how to do it on our side on Linux. There should be 3 states: low base and performance. So we should even "hear" how "fan" will move less and fast.

For example, i never heard on all my tests that fans start to be louder they still same speed.

@xeno74

Good find! Need to check what we have in /sys/class/drm/card0/device/power_method by default .. maybe even we have DPM there we just didn't enable it on boot.

Btw when you run glxgears and doom3: do you hear any change in the level of "loud" from GPU fans?

[kas1e]

@xeno
checked /sys/class/drm/card0/device/power_method and it has "dpm" mean dynamic power management. i assume this one is inbuild by default in our kernel and that is what i want to disable for my own tests. So what i need most to be able to disable that and use it when need low ones or high ones etc.

Checed also /sys/class/drm/card0/device/power_dpm_state t says "balanced" :

Where "parameter" can be:

battery (a set of performance levels targeted for optimal operation on battery)
balanced (a set of performance levels targeted for optimal everyday use)
performance (a set of performance levels targeted for the highest GPU performance)

So of course with balanced our glxgears and other "small" tests didn't show the full power of RadeonHD6970 only in doom3 seems this raised resources.

Now just do:

1. echo performance > /sys/class/drm/card0/device/power_dpm_state
2. reboot.
3. cat /sys/class/drm/card0/device/power_dpm_state

And this damn show again is "balanced"! So changes auto-changes on boot seems so?

Also tried to change /sys/class/drm/card0/device/power_dpm_force_perfomance_level from default "auto" to "high" and to "low" (with reboots of course) but after reboot values remain unchanged the same as with power_dpm_state. Like kernel by on boot set something and i can't overwrite it.


if i do "dmesg | grep dpm" then i have:
[drm] radeon: dpm initialized.

So seems indeed inbuild by default. But why i can't change shit and all changes on defaults after reboot (while as i read in google - shouldn't. instead it should be saved and taked into account).

[xeno74]

Btw when you run glxgears and doom3: do you hear any change in the level of "loud" from GPU fans?

Yes, definitely.

Have you tested glxgears with vblank_mode=0 yet?

Code: Select all

vblank_mode=0 glxgears

Just for info: Glxgears is not a benchmark Another link

[xeno74]

FYI:

Displays FPS, GPU, CPU, TEMP etc:

Code: Select all

GALLIUM_HUD=simple,fps,cpu ./dhewm3

Code: Select all

GALLIUM_HUD=GPU-load,cpu0+cpu1+cpu2+cpu3,fps,sensors_temp_cu-radeon-pci-0100.temp1 ./dhewm3