I've been working on an add-in and during testing, I have some test files that I test over and over (state changes, check in, check out, etc). I have noticed that as the version count increases, certain EPDM operations slow down significantly. For example, clicking the 'Change State' button in the EPDM task pane in SOLIDWORKS would result in a five second delay before listing the available transition (there is only one for this test). This was a file with 300+ versions. As soon as I performed a Copy Tree to make a new file, the response time was instantaneous.
Is this a known problem? I imagine that many EPDM users have files with lots of versions, especially if they have hardware libraries and such. I don't know if the impact would be multiplied if the file is part of an assembly.