Piwik Archiving Question

I’ve got a quick question about archiving. Does it take longer to archive if there are more records in the database, or just more records to process?

Right now I have a site with ~3500 visitors per day, set to archive every 15 minutes (by Bash script). This archive process takes roughly 2-4 seconds right now, but I have less than 24 hours of records total, archived in the database (just installed yesterday). Will it take longer when I have a week of records? A month? Six months? A year? Or will the archive script always go at the same speed (in relation to how many new records it has to process)?

Archiving will process data since the last time it was run. Assuming your traffic is consistent it will take approximately the same amount of time every time it runs. This is the point of archiving on a regular basis, to prevent it from having to go through a lot of historical data and taking a long time to run.