I’ve noticed consistently (regardless of which server or service provider I’m using) that the rate at which I’m able to download Headers through NNTP is drastically slower than the rate at which I’m able to download actual posts/files. Is there perhaps something I’m doing wrong or some other logical reason why Header download rates would be a lot slower than file download rates?
The problem is almost certainly at the NNTP server end. The server has to do a lot of work to go thru its server files and pluck out the headers, assemble into packets, etc. Plus it’s doing this for you and thousands of other clients at the same time. Note also that this files are dynamically changing as new messages arrive at the server and old ones deleted. There’s a lot of OS overhead in keeping things from getting scrambled. That’s a lot of work.
In short, it’s not a transit time issue but a server load issue.