Many default settings for web servers and PHP are not tuned for high-speed file transfers.
If your local speeds are fine but external downloads are slow, the network is likely the culprit.
Slow downloads can also be caused by the server struggling to find or track files. nextcloud download slow
Ensure your web server (Nginx or Apache) is configured to use HTTP/2 . This allows for multiplexing, which lets the browser download multiple small files or segments in parallel over a single connection. 2. Database and System Tuning
If you have upgraded your Nextcloud instance multiple times, your database might be missing critical indices. Run sudo -u www-data php occ db:add-missing-indices to optimize your database. Many default settings for web servers and PHP
Ensure your server has enough physical RAM. If the system starts using swap space on the disk, performance will drop dramatically. 3. Network and Proxy Bottlenecks
Implementing Redis for both local and distributed caching can significantly speed up the web interface and file metadata handling. Ensure your web server (Nginx or Apache) is
Nextcloud requires a minimum of 128MB per process, but 512MB or more is recommended for better performance. You can set memory_limit = 1024M in your php.ini file to provide more breathing room for large file handling.