Why does Nici download 2 pages simultaneously?
If Nici is already downloading a page from a particular host, it will pick a page from a different host to download simultaneously. This means that if one server host is slow, the other will take up the slack. The more pages that are simultaneously downloaded, the higher the chance that server blocking mechanisms and other errors will occur. While Nici intelligently retries errors, and can request only the parts of an image that have not already been downloaded, this does reduce overall performance. Nici will create extra simultaneous downloads for certain actions, for example if you tell Nici to download the page now, or try for more.
