Increasing Speed of initial seeds

R

ru42

Member
Greetings!

Ok, so I got to thinking about download speeds.  The 10 disk Treasures that recently posted is what go me started.  Lots of us were pulling the initial download and it took quite a bit of time.  During that time and all the way up to now I have had a pretty heavy load on my computer.  I got to thinking, what is the best way to get something new out there fast.  So, I played with some numbers and wanted your thoughts:

Facts for this hypothetical scenario:
File size 1000MB
Upload Speed Load Max 20 MB/min

Ok, so lets say I am a single seeder for this 1000 MB file and I can only serve up 20MB/min.  20 people want my file so taking my load capability (20 /min) and divide that bny 20 people and each person can get 1 MB per min.  Total download time for all 20 people is 1000 minutes.

Same facts but lets say I cap the number of connections to 5.  So, my 20/min divided by 5 means each person can get 4 MB/min for a total download time of only 250 minutes.  (75% savings in time but a reduction of completions by 75%)

But now we have 6 seeders (myself plus 5).  Using the same statistics the 6 of us could feed an additional 30 people in an additional 250 minutes.

So, after 500 minutes (half the time) we have 36 completions rather then the first set of numbers which would only be 21 people in 1000 minutes.

To me, it seems like when a file is released we could increased the speed of the distribution by limiting the number of people connected for at least the first round of seeding.

Thoughts?  I know there are all kinds of variables in the process and no way I could account for all of them.  In a shotgun method my numbers seem solid.  But in reality......what do you think?

RU
 
Sounds far to logical to be true,  I joined when there was 1 seed and I think 40 peers, I had no link to the seeds (7 by then) until I'd downed over 70% of the file. 

I think the flaw in your calculation is assuming only seeds provide content, when in fact most bit torrent content is provided by incomplete peers 

also it assumes that its the same 1/5th of the  20MB sent from the seed to all of your 5 peers, when its likely that the whole 20mb sent will be different.  Which means that after minute 1 there are 20 megs avaliable from the peers with no connection to the seeder needed.

however I don't see any harm in the seed limiting upload or  connections if you could designate the peers connected too.
 
or you first send it to me for initial seed.. I can seed with up to 70MB/min on my torrent line  ;D
 
>:(  Theres no smiley for the rest of my thoughts!!!!!!! 70MB  I'm fine downing but uploading is 1/5th on my async connection.  What's your D/L
 
I'm not so sure that limiting the number of connections really helps.

If I understand bittorrent correctly...

You as the initial seeder say can only seed at 20 MB/m.  If 20 people are connected you should be able to send to each of them at 1MB/m, that's true, but you are not taking into account, that bittorrent SHOULD give each of those 20 people a different portion of that file.  So, after 1 minute, each of those 20 poeple will be able to seed a different 1MB portion of that file, so they can all connect to each other and get that, instead of downloading from you.  SO, assuming they have the same speeds, after one minute, they can seed that portion of the file, and you can seed portions not yet distributed, OR two people are now able to serve up the same portion of the file.

My head hurts thinking about it, but I believe that is the way the bittorrent is supposed to work, which explains the whole "swarm" concept used by bittorrent.
 
Dolby - I think I speak for most (all) of us, that surely must be nice.

I see what a couple of you mentioned.  I was looking at it very linear while BT strength is the ability to distribute segments non linearly.  That makes sense.  But what about this.

I think the key is the initial seeder.  A torrent will only distribute as fast and the original seed can get all parts out there.  So, the key it would seem to me is to get round 1 out there as fast as possible.  I didn't watch the clock on the Treasures torrent but it seemed it took me around 18 hours to get the whole file and I was downloading it pretty early in the release.  I know some/all of us (except Dolby) have some sort of upload limits; this is not a criticism just a fact.  So, if the initial upload can get out there quicker, to be mutually shared quicker, seems like BT would go faster.

If just that one initial person limited his connection to 5 then those 5 would get it relatively faster.  Those 5 however, do not limit the amount of connections.  They would get all segments faster and therefore the multiply effect would be faster if each of them were serving multiple people and so on and so on.

This scenario would be moot for those who have strong uploads (Dolby) and decent uploads (most ISPs) but I have read some that have very limited speeds uploading.  This technique might work better.


I think I will experiment with some uploads.  I will upload one with X connections and watch the speed and then try it again (different video, relatively same size) with some portion of X and see what happens.

RU
 
you can try that ...maybe it works better


but I'll try to keep it simple (tired from work no energy to type so much  :P)

I think when the first complete set of parts of the initial seeder was distributed .. the speed already multiplied inside the swarm and the torrent is going nice ...

azureus has a nice option it's called forced super seeding somehow azureus figures out what peers in the swarm have the best speed and feeds them more parts .. but all together distributes a whole set of parts in the swarm .. so if one peer with essential parts dropps out, mainly those parts are then seeded into the swarm
 
Just a crazy thought that i've actually been thinking of for a while.  Why don't we have a couple initial seeders for some of the larger releases, like let's say martin's tribute vids.  Possibly set up a central location where a few folks can grab it and start start seeding as a group so everyone else can get very quickly and help continue seeding.  I know dolby has an awesome upload speed, I have a fairly good upload speed as well, and I know a few others do as well.

Just a thought...

Geoffrey
 
This has happened for some of releases, notably the Disneyland Forever Project.  I think it's more of an event thing really since coordination is necessary.
 
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