Very(!) slow ramp down from high to low clock speeds leading to a significantly increased power cons

Graphics / Linux Linux
124

Hi Aintmarks,

Currently, we are able to reduce gpu clocks from ~38 secs to ~14 secs which is a good sign and will continue to investigate for further improvements.

I also tested on notebook having Alienware 17 R5 with driver 418.74 and reg key enabled on terminal, it took 14 secs to ramp down clocks.

Below is the o/p for reference.

oemqa@dbian:~$ grep GL_ExperimentalPerfStrategy /etc/environment ; echo $__GL_ExperimentalPerfStrategy ; while true ; do nvidia-smi dmon -c 1 ; timeout 3 glxgears ; for i in $(seq 1 50) ; do nvidia-smi dmon -c 1 ; sleep 1 ; done ; done
1

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0     9    47     -     0     9     0     0   405   139

Running synchronized to the vertical refresh. The framerate should be
approximately the same as the monitor refresh rate.

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0    40    48     -    11     2     0     0  4006  1442

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0    34    48     -     0     1     0     0  4006   949

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0    35    48     -     0     1     0     0  4006   949

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0    34    48     -     0     1     0     0  3802   949

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0    34    48     -     0     1     0     0  3802   949

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0    34    49     -     0     1     0     0  3802   949

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0    28    49     -     0     1     0     0  2999   822

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0    28    49     -     0     1     0     0  2999   822

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0    13    49     -     0     4     0     0   810   822

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0    13    49     -     0     4     0     0   810   822

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0    13    48     -     0     4     0     0   810   822

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0     9    48     -     0     9     0     0   405   189

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0     9    48     -     0     9     0     0   405   189

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0     9    48     -     1     9     0     0   405   139

gpu pwr gtemp mtemp sm mem enc dec mclk pclk

Idx W C C % % % % MHz MHz

0     9    48     -     0     9     0     0   405   139

^C
oemqa@dbian:~$

Can you please perform below steps precisely -

  1. Boot up system and make sure there are no applications running.
  2. Open a terminal and verify output of command echo $__GL_ExperimentalPerfStrategy. It should result 1.
  3. Execute below command to verify secs to ramp down gpu clocks.

grep GL_ExperimentalPerfStrategy /etc/environment ; echo $__GL_ExperimentalPerfStrategy ; while true ; do nvidia-smi dmon -c 1 ; timeout 3 glxgears ; for i in $(seq 1 50) ; do nvidia-smi dmon -c 1 ; sleep 1 ; done ; done

If you will open/close applications continuously, it will take time to ramp down clocks.
Please make sure to reopen and close app after a pause of 45-50 secs to notice change