Advanced: improving downloads
Improve download speed and support resuming by using XSendFile
If you have access to edit your Apache or NGINX sites and configurations, it's recommended that you enable XSendFile (or X-Accel) so the files are served directly, eliminating php as a middle-man, which can be the cause of slow, interrupted downloads, or corrupted files (specially when downloading very large files).
After enabling the module, make sure to also enable the corresponding option in
Options -> General.
If you are using NGINX, ProjectSend will give you the code that you need to add to your server block.
Example: X-Accel download method selected for nginx
A few resources on how to get started if you are not familiar with X-Accel or XSendFile: