Martin said:HWiNFO doesn't report NVIDIA parameters, because the GPU says that it's not enabled. So my assumption is that your NVIDIA GPU is not utilized in that situation.
Try other games or some benchmarks and see what happens.
If MSI Afterburner reports GPU values in that state, then I think it's accessing the GPU and thus keeps it awaken. HWiNFO on the other hand doesn't touch the GPU if it's disabled to preserve power - this mode of operation doesn't have influence on the system nor raises power usage by waking the GPU up when it should be sleeping, which I believe is what the users desire.
I would like to go on, the GPU (GTX 980M) is used for diablo, FFXIV, Guild Wars 2, Heroes of the Storm, and the Witcher 3. HWiNFO does not and will not give consistent readings on windows 10. MSI Afterburner is... But I get no output with HWiNFO as I did in windows 7, windows 8, and windows 8.1. While in game, with it using my GTX 980M I get this: (See Screen Shot) Also values do occasionally for 1 second read on HWiNFO that's why you see that they are currently zero. Anyway let me know .