Confluence migrator performance problems

When I upload an XML file that is 700 MB, the import process takes an extremely long time - more than 20 hours. If I upload, for example, a 300 MB file, the import process takes about 40 minutes. What could be causing such a long import time for larger files? And what are the parameters that should be increased to ensure a successful import for large confluence spaces? Currently, the configuration is xwiki.store.cache.capacity=5000
-Xms1536m -Xmx3072m.

Do you mean Confluence Migrator Pro ?
I also have had no goes testing import from Confluence while trying to use the Confluence Migrator Pro extension, in trial mode.
Whereas memory is concerned, we have way enough, that’s gigabytes (8, and 4, or 32 available, I think).
Processor cores were much in use. He have raised their number in the virtual machine.

I have reverted import trials method to using the manual method, consisting in installing the import under /usr/lib/xwiki/data and doing manual imports, which tends to work better.

No we ar using Confluence Migrator - https://store.xwiki.com/xwiki/bin/view/Extension/Confluence%20Migrator/

I have tried the Pro version in trial mode, and also the manual method, that seemed to work better when testing importation of several spaces, from 500MB up to about 4GB. ( Confluence to XWiki migration guide: from export to customization - XWiki ). Maybe would you like to give it a try?