NVIDIA Turing/1660 Ti: forcing maximum power saving/minimum performance mode

I’ve always used this option and it worked with older cards however with Turing it does the opposite: it forces the GPU to stick to maximum performance:

Option "RegistryDwords" "PowerMizerEnable=0x1; PerfLevelSrc=0x2222; PowerMizerLevel=0x3; PowerMizerDefault=0x3; PowerMizerDefaultAC=0x3"

I’ve also tried a kernel module option:

options nvidia NVreg_RegistryDwords="PowerMizerEnable=0x1;PerfLevelSrc=0x3333"

With no success.

So, how can I force maximum power saving/minimum performance mode with Turing under Linux? I’m running NVIDIA drivers 450.57. It looks like Xorg options are being ignored.

I’ve replaced all the Xorg options with just one kernel module option:

options nvidia NVreg_RegistryDwords="OverrideMaxPerf=0x1"

which has solved the issue for me.

My full kernel module options are: options nvidia NVreg_RegistryDwords="RMUseSwI2c=1; OverrideMaxPerf=0x1" because it’s the only way to allow i2c (gddccontrol) to work properly.