Fix Nvidia GPU High Idle Power Consumption
I was reading some news about AMD RX 7000 series GPUs having high idle power consumption as users report that the idle power consumption can be as high as 100W. My immediate reaction was like: Isn't that normal? My Nvidia GPU also idles at about 120W. A quick search reveals that this shouldn't be the case.
The first potential culprit that comes to my mind is undervolting, which doesn't make sense because undervolting actually reduces power consumption. But it's the only change I made as far as I can remember so I reverted the undervolting change just to verify. And no — idle power draw didn't change.
To take a closer look, I opened HWiNFO and monitored different metrics of the CPU for a while. One thing quickly stood out — the GPU clock always stays at boost frequency, even under no load. With this information and some more googling, I found out that the issue was due to the power management mode setting (under Manage 3D settings in Nvidia Control Panel): instead of "Normal" (the default value), it was set to "Prefer maximum performance". After changing back to the default value, the clock speed finally went down and power consumption dropped to around 35W, just as it should.
Changing this setting is something I picked up when I actively played CS:GO. For the context, CS:GO is a poorly optimized game where FPS absolutely matters and players do whatever they can to get more FPS. Some FPS optimization tips are apparently bullshit while others are close to dark wizardry but this one seems rather reasonable so I always did it after reinstalling GPU driver. Since I don't play CS:GO anymore, there's no reason to change this setting.
But does "Prefer maximum performance" mode actually do anything? To me there's no noticeable difference, even when I was playing CS:GO. All it seems to do is to keep the clock at the maximum which draws significantly more power at idle. For gaming, the clock will boost to max frequency anyway. In theory higher clock should translate to better performance but performance doesn't matter if you are only browsing the web or watching YouTube videos. Your GPU is doing more work for nothing and you are simply wasting power. Don't do this.