It's been a long time since I ran benchmarking on this old computer, anyway, on my outdated i7-4770K at 3.5 Ghz from 2013, it took me 32 seconds here. Generally we use cloud services to do this stuff now and it's faster, but if your existing process is taking you minutes to do it then this will really help save you time in the future.
I don't know how long these files will be available so you will want to grab them now rather than later - for windows 64bit only..
https://www.ultraflix.com/Bif_File_Tool_BDS_v2.zip
READ THE README.TXT FILE
https://www.ultraflix.com/Bif_Creation.mp4
-- 32 seconds for a 20,000 leagues under the sea, 2:06:55, 320 x 240 HD Bif file, making 760 jpgs, combining into a bif file of 3.7 MB in size