Background Intelligent Transfer Service(BITS) download speed really slow?

Question

I am using BITS 2.1 version, on Window XP SP3. I have 2 files, to download using BITS, one is around 9 Mb, other around 1 Mb. I created a BITS job in my C# code, added the 2 files to this Job and started the download. The job has a priority of Normal. The 9Mb file gets downloaded quickly but the other file does not start downloading for a loooong time (around 20 min!). If the Job priority is made to Foreground, both downloads happen in like 3-4 seconds.

Does anyone have any clue why BITS behaves like this. 20 minutes seems to be really long for such a thing.

Answer 1

You answered it in your blog, but never came back to post your results

http://theraneman.blogspot.com/2010/07/is-your-background-intelligent-transfer.html

BITS uses Round Robin algorithm within a queue of jobs of same priority. Thus having just 1 file improves the situation for BITS.

If you are responsible for building a tool which uses BITS to download stuff from a server on client machines, and you do not have control over the network policies and all that, at least try to zip all the files into 1 and download it. It surely improves the speed. If you are allowed to change the priorities of jobs, give an option to the user saying something like “Download Now”, which would change the Job priority to Foreground and things would come blazingly fast on the machine.