Using long sample files

I know this is not what renoise is made for but I want to ask - if I cut a big file down into a small sample, it seems to behave like the file is still big. Is it better to cut out of a big file then dispose of the huge original?

As long as you use autoseek, you should be fine.

what do you mean by “it behaves like it is still big”?

Lets say I have an audio file that is 3 minutes long - a vocal. If i cut away all the audio except the chorus; renoise still seems to take time loading and saving its as if its still a mahoosive file.

maybe you are using some of the sample compression options?

check
Edit => Preferences => Files => Song/Instrument Export section.

compressing and decompressing file may take many time