To improve the performance of your e107 website, you can make the following changes:
Enable caching for your e107. You do this from the Admin area > Settings > Cache. Once there, you should check Cache data saved to disk file and click Set cache status to save the change.
Keep the number of active plugins as low as possible. Use only the plugins you really need.
Optimize your e107 database
Decrease the number of external and internal links on your pages. Leave only the most important ones.