Using RTX 2080 Ti 11 GB + Ryzen 9 CPU 3900 and 700 section size in split frame setting, it can render 12 interpolated frames in one minute for 1080p 24 fps video into 60 fps.
Win 10 /// RTX 2080 Ti Strix OC 11Gb (water cooled) / Ryzen 3970x / 128 RAM / m.2 970 Evo Plus SSD
Test file 0,5sec 1080p 30fps x2 interpolation (15 frames into 29). 15 frames original from the video. This means that only 14 new frames was generated.
Split frame into section setting:
@ 850x150 - 3m:03s ~ 12 frames rendered about 2m:37s
@ 700x150 - 3m:26s ~ 12 frames rendered about 2m:56s
Even if calculate the processing of all 29 frames during interpolation, your PC configuration completed this task faster.
Maybe it depends on the content in the image? Otherwise, I don’t understand why my computer rendered frames much slower than yours ...
Recently, I try to render 1920x1080 film from 24fps to 144fps (interpolate 8x setting)
1%| | 906/90011 [15:31:38<6264:55:24, 253.11s/it, file=0000102728.p
1%| | 907/90011 [16:06:56<20110:57:51, 812.53s/it, file=0000102811.p
......
1%| | 912/90011 [17:04:47<24265:53:08, 980.45s/it, file=0000104146.p
1%| | 913/90011 [18:15:10<48336:48:31, 1953.05s/it, file=0000105397.p
1%| | 914/90011 [18:19:23<35713:04:01, 1443.00s/it, file=0000107065.p
1%| | 915/90011 [18:21:27<25925:17:02, 1047.53s/it, file=0000107149.p
....
1%| | 922/90011 [18:36:13<5016:15:13, 202.70s/it, file=0000107441.p
1%| | 923/90011 [18:38:22<4463:26:52, 180.37s/it, file=0000107482.p
I find that the processing time is varying from 180s/it to 1953s/it.