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Old January 21st, 2010
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Quote:
Originally Posted by Total Eclipse View Post
When creating your torrent, by default it will be set up to "automatcially" set the size of chunks... I believe this is true of all such utilities. I advise - after reading enough help files - to set it to something like 512 kB. This does three things: first, it results in a lot less "lost" or "wasted" data. If I were to attempt to download your torrent and your chunk size was 4 MB and there was any sort of error or connection issue, I'd have to start downloading that 4 MB all over again. This is rather bothersome if I already had 3.98 MB before having to do that. Secondly, smaller chunks will save bandwidth on your end and on the client end while your program of choice will be able to more accurately depict your share ratio. Thirdly... for aesthetics alone... progress indicators will update more quickly
While I'm sure your intentions are in the right place here, you should surely take into account what else small piece sizes do to big torrents. First off the torrent file will be huge. Second, while yes if you are interrupted while downloading a piece you will most likely lose that data, lets do a little math having e.g.

A 8.53GB torrent. In my case I lost 55.18MB while downloading it. It was piece size of 2MB = 4366 pieces. Protocol on a bigger piece torrent will generally use around 0.3% (messages back and forth between clients, which depend on a lot of things) approx. 26.2MB

You want 512KB pieces i.e. 17464 pieces. Well that means 4 times as many messages. So 26.2MB x 4 = 104.8MB so 78.6MB more than with 2MB piece size.

Now let's go back to the beginning where I said I lost 55.18MB. Let's say you lose 4 times less with 512KB pieces, so 13.8MB.

512KB pieces = 104.8MB + 13.8MB = 118.6MB waste
2MB pieces = 26.2MB + 55.18MB = 81.4MB waste

IMHO the uploader should have made the torrent 4MB pieces as around 2000 pieces works quite well when minimizing wasted data. But you probably use some bad client like Limewire, so you can't see all the overhead used on small sizes.

Last edited by Sleepless; January 21st, 2010 at 05:58 PM.
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