[ad_1]
@andreas-2013 All preload is doing that it visit’s your site programmatically. So, it will take the same amount of resources if you visit the pages manually.
The preload doesn’t run as a single task. Once the PHP script reaches the time limit (max_execution_time), the remaining URLs are scheduled to preload later. We do see the possibility and increase the time limit to 30 minutes. What you have done is that increase the interval between batched preload tasks.
If you don’t want to run a single preload task for 30 minutes, then you can reduce it by defining a constant WP_OPTIMIZE_SET_TIME_LIMIT to your desired seconds.