Does it depend upon the number of upload slots you allocate?

Does it depend upon the amount of bandwith you allocate?

Does it depend upon the number of downloads you are actively downloading?

Does it depend upon the number of files you are sharing?

Does it depend upon the number of download that you are trying to download but are not because there are no sources available?

What else besides the obvious (how much download bandwith you have) does download speed depend upon?