Hi,
Yes, Showtime Image Gallery for Joomla is designed to perform great even with a large number of images/galleries. More specific:
1. Images are uploaded in chunks. An image will get uploaded even if it's huge.
2. Images are uploaded in sequence. This means that it can upload any number of images.
3. All database queries are optimized and use indexes so the application remains fast even if there are 1000s of galleries.
However, there are some things to consider:
1. Showtime Image Gallery does not have limitations but servers do. Most of the servers have a maximum limit of data you can send. This can cause issues when you try to save a gallery with a lot of images. In that case, all you need to do is increase that limit on your server setup. Or ask your hosting provider to do it for you. If you face this issue please let me know so I provide the technical details.
2. All servers are not the same and have their performance limits. When those limits are reached there is nothing that can be done even if the application is optimized.
In any case, if you experience any issues when data grows please let me know so I can help.
Regards