Mobi dictionary conversion to Epub taking forever

[Inkpad3]

Converting mobi dictionary to epub take forever :
I want to know why converting mobi dictionary to Epub with Calibre take so long and consume so much memory ?

I took a mobi dictionary of about 13MB and it took like 2/3 days before it output it to Epub format. It was really slow splitting page... and after 8,500 pages and 4 days i decided to stop the conversion.

It could have taken 20-40 days to finish the conversion as i suspect they were a word definition in each page as i could see in other dictionaries.

It took up to 13GB of memory and constant 5GB on my pagefile (went from 16GB to 21GB). It could have taken more swap disk but my OS SSD was full.

Why mobi dictionary conversion or dictionary conversion take so long and requiere so much memory ?

Unpacking mobi files seems a better solution :
I used mobi unpack Calibre plugin and conversion is very fast.

I took a 16MB english dictionary and took a few seconds to unpack mobi.
It launched parallel calibre processus to convert it to epub as well and took around 13GB of memory... There were no progress bar and even after quiting Calibre the proces was still there.

I stoped it and i was then able to take the 90 MB html and load it on google chrome to see it was complete and it was.

It's taking forever to load on Sublime text though. It has to check every tags and i guess there is a lot. If it was on Notepad++ or even worse on Notepad it would be a real nightmare.

Recently i was able to load a 90 MB html dictionary on this software and convert it easily to XDXF format then to Pocketbook format with pocketbook converter.

I guess i'll have to go that way to convert dictionaries.