Re: DPM on Radeon HD6570

[Grigori Goronzy <greg@chown.ath.cx>]

On 21.08.2013 16:31, Boszormenyi Zoltan wrote:
> Hi,
>
> I read this Phoronix article:
> http://www.phoronix.com/scan.php?page=article&item=amd_hd6000_dpm&num=1
>
> Congrats to the progress achieved so far.
>
> However, I can see an interesting deviation for HD6570 from the
> observed trend of other chips.
>
> r600g can reach 80+ percent of the performance of Catalyst
> for most HD6xxx chips except for 6570, where the performance
> is around 10-20 percent.
>
> Do you have a theory about this difference?
> Maybe DPM doesn't work as intended on HD6570?
>

There are some ways to check if DPM functions correctly.

The kernel log (dmesg) contains a dump of the PowerPlay tables, search 
for "power state". It's possible that tables aren't read correctly or 
flaky to start with.

You can also monitor the precise runtime power level (clocks and 
voltages) of the GPU with /sys/kernel/debug/dri/0/radeon_pm_info. Maybe 
dynamic switching does not work for some reason, and the GPU always uses 
the lowest level even under load. Just run some demanding OpenGL app and 
check that file to see if the GPU switches the power level.

You should probably file a bug on bugs.freedesktop.org (product DRI, 
component DRM/radeon) and attach dmesg output and anything else that 
might be useful.

Best regards
Grigori