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.