How to find out reason why cpu and gpu usage is very low during export?

hello my computer spec is ryzen 3600x cpu, 6700xt gpu, 32gig of ram and 512nvme ssd on bootdrive and 1TB of ssd on storage drive.

I am trying to render 4k/60fps, 1 to 2min video recorded from iPhone 12 pro, it has fadein(audio and video), fadeout(audio and video), opacity, corner pin, position, gain/volume filter, text w/filters. there are 3 video tracks, 1 for text track, overlay video track and the main video track, the overlay video track came in in the middle after few 20s and it has fadein, fadeout, opacity, corner pin and position filter, the rest just only fadein/fadeout and 2 audio tracks with fadein/fadeout and gain/volume.

when exporting, during the first period it was very fast, cpu went between 80% to 100% but then it just drop to between 10 to 20% after around ~25% completion, gpu always stay between 0-4% but most of the time is 0%, ram stays around ~11gig and the exporting just gets slow from 25% completion onward until like 92% it speed up until 100%. I have the hvec_amf codec selected and also detected when clicking the detect button of hardware encoder configure section, hardware encoder also checked as well as parallel processing, export option is using the stock HEVC Main Profile with only parallel processing and use hardware encoder checked and export time of 1min30s 4k/60fps video took like almost an hour(finished watching kitchen nightmare burger kitchen episode and it still exporting).

this is the log copied at 50% completion

[wav @ 000001c18eae8180] parser not found for codec pcm_s16le, packets or times may be invalid.
[wav @ 000001c18ebd2740] parser not found for codec pcm_s16le, packets or times may be invalid.
[producer avformat] audio: total_streams 1 max_stream 0 total_channels 1 max_channels 1
[AVIOContext @ 000001c18eae8500] Statistics: 294956 bytes read, 2 seeks
[mp3 @ 000001c18f019040] Skipping 0 bytes of junk at 237.
[mp3 @ 000001c18f01f6c0] Skipping 0 bytes of junk at 237.
[producer avformat] audio: total_streams 1 max_stream 0 total_channels 2 max_channels 2
[AVIOContext @ 000001c18ec46840] Statistics: 98304 bytes read, 1 seeks
[AVIOContext @ 000001c18ebd2b00] Statistics: 294956 bytes read, 1 seeks
[mp3 @ 000001c18f019040] Skipping 0 bytes of junk at 237.
[mp3 @ 000001c18eae8f00] Skipping 0 bytes of junk at 237.
[producer avformat] audio: total_streams 1 max_stream 0 total_channels 2 max_channels 2
[AVIOContext @ 000001c18ec46840] Statistics: 98304 bytes read, 1 seeks
[producer avformat] audio: total_streams 1 max_stream 1 total_channels 2 max_channels 2
[AVIOContext @ 000001c18ead8d40] Statistics: 495441 bytes read, 2 seeks
[chain avformat-novalidate] I:/shares/keyboards/chalice40/typing-test-video.MOV
    checking VFR: pkt.duration 10
[hevc_amf @ 000001c18ec71900] AMF initialisation succeeded via D3D11.
[h264 @ 000001c18f412a80] Reinit context to 2592x1040, pix_fmt: yuv420p
[h264 @ 000001c18f410e80] Reinit context to 2592x1040, pix_fmt: yuv420p
[AVIOContext @ 000001c1acf8dcc0] Statistics: 125268 bytes read, 2 seeks
[chain avformat-novalidate] I:/shares/keyboards/chalice40/typing-test.mov
    checking VFR: pkt.duration 100
[h264 @ 000001c18f412a80] Reinit context to 2592x1040, pix_fmt: yuv420p
[wav @ 000001c224920380] parser not found for codec pcm_s16le, packets or times may be invalid.
[wav @ 000001c224921140] parser not found for codec pcm_s16le, packets or times may be invalid.
[producer avformat] audio: total_streams 1 max_stream 0 total_channels 1 max_channels 1
[AVIOContext @ 000001c1acf8d740] Statistics: 294956 bytes read, 2 seeks
[link swresample] 1(mono) s16 48000Hz -> 2(stereo) f32le 48000Hz

log copied at 100% completion

[wav @ 000001c18eae8180] parser not found for codec pcm_s16le, packets or times may be invalid.
[wav @ 000001c18ebd2740] parser not found for codec pcm_s16le, packets or times may be invalid.
[producer avformat] audio: total_streams 1 max_stream 0 total_channels 1 max_channels 1
[AVIOContext @ 000001c18eae8500] Statistics: 294956 bytes read, 2 seeks
[mp3 @ 000001c18f019040] Skipping 0 bytes of junk at 237.
[mp3 @ 000001c18f01f6c0] Skipping 0 bytes of junk at 237.
[producer avformat] audio: total_streams 1 max_stream 0 total_channels 2 max_channels 2
[AVIOContext @ 000001c18ec46840] Statistics: 98304 bytes read, 1 seeks
[AVIOContext @ 000001c18ebd2b00] Statistics: 294956 bytes read, 1 seeks
[mp3 @ 000001c18f019040] Skipping 0 bytes of junk at 237.
[mp3 @ 000001c18eae8f00] Skipping 0 bytes of junk at 237.
[producer avformat] audio: total_streams 1 max_stream 0 total_channels 2 max_channels 2
[AVIOContext @ 000001c18ec46840] Statistics: 98304 bytes read, 1 seeks
[producer avformat] audio: total_streams 1 max_stream 1 total_channels 2 max_channels 2
[AVIOContext @ 000001c18ead8d40] Statistics: 495441 bytes read, 2 seeks
[chain avformat-novalidate] I:/shares/keyboards/chalice40/typing-test-video.MOV
    checking VFR: pkt.duration 10
[hevc_amf @ 000001c18ec71900] AMF initialisation succeeded via D3D11.
[h264 @ 000001c18f412a80] Reinit context to 2592x1040, pix_fmt: yuv420p
[h264 @ 000001c18f410e80] Reinit context to 2592x1040, pix_fmt: yuv420p
[AVIOContext @ 000001c1acf8dcc0] Statistics: 125268 bytes read, 2 seeks
[chain avformat-novalidate] I:/shares/keyboards/chalice40/typing-test.mov
    checking VFR: pkt.duration 100
[h264 @ 000001c18f412a80] Reinit context to 2592x1040, pix_fmt: yuv420p
[wav @ 000001c224920380] parser not found for codec pcm_s16le, packets or times may be invalid.
[wav @ 000001c224921140] parser not found for codec pcm_s16le, packets or times may be invalid.
[producer avformat] audio: total_streams 1 max_stream 0 total_channels 1 max_channels 1
[AVIOContext @ 000001c1acf8d740] Statistics: 294956 bytes read, 2 seeks
[link swresample] 1(mono) s16 48000Hz -> 2(stereo) f32le 48000Hz

I tried both checking/unchecking use hardware encoding and parallel processing and exporting speed somewhat the same except with parallel processing, cpu can go up to 100% while without it only reaches about ~55% and I also tried exporting 1080p instead of 4k and the time estimation still the same and resource usage still the same which is weird, isnt exporting lower resolution supposed to be faster? however I tried hiding the overlay video track that has the most filters and somehow it went very fast all the way but gpu still 0% only cpu reached very high and export time only ~3min for 4k/60fps but the overlay video is not 4k itself the main video track is, is it because of some filters I used?

so how to find out why resources isnt properly utilized?

Read the FAQ on the web site.