Pr won't use GPU for palyback

By default CLog 3 footage is 10-bit 4:2:2 HEVC. This means that your system does not support hardware decoding of 4:2:2 footage at all. You should not have gotten an F or KF CPU if you intend on using hardware decoding of 10-bit 4:2:2 HEVC footage because the F/KF CPUs do not have Quick Sync hardware decoding at all (it is permanently disabled, along with the associated integrated Intel UHD Graphics 770, during manufacture of the CPU due to a defective integrated graphics output). And Nvidia chose not to support 4:2:2 hardware decoding at all in its NVDEC.

In other words, those results you came up with are about as good as you can get with that particular footage on your system.

right click the video file in pp and select properties. you will see the details in  "video codec type" row

do you know how do I check if it's in 4:2:2 or not?

It looks like it's working to me. I see 5%, 13% and 17%. That might be as good as it gets. It would be nice if both items could crank out, but that's not the way it works. Only certain things are GPU accelerated. Changing frame size is one, I believe Ward stabilizer (edit: Not Beaver's Father - Warp Stabilizer) 🙂  is also... there's a few more, and a document around on that.

Is that footage in 4:2:2? If so, neither Premiere Pro nor Nvidia will use hardware acceleration at all. Instead, all playback of that footage will go entirely to the CPU with your system no matter what.

That is because for some strange reason Nvidia's NVDEC supports 4:2:0 and 4:4:4 - but not 4:2:2!

PS. I'm editing a 4k 60fps clog 3 footage.