The render settings are the same: Internet UHD 2160p 25 fps AMD VCE. The video files are AVC 3840 x 2160 (8 bit) in mov container from Panasonic Gh5II and G9. The pc specifications are in signature. I was wondering if anyone has seen the same behavior in rendering, the speed went from about 60 to 32 fps.
I'm wondering if it's an issue with amd renders or timeline processing. I don't have my 6900xt installed at the moment to test that. My only suggestion is to make sure video gpu says optimal and i/o gpu is set to auto so it selects same gpu as video prefs. Also, what about the subsampling... 4:2:2 avc is a problem for any gpu.