Is BT really that slow?

[lavalyn]

Considering that my group uses only BitTorrent for distribution, and no fserves, I occasionally get requests to open an IRC channel for faster distro and such. We personally like BitTorrent but other groups swear by it, that's fine.

But the most common complaint with BT is that it's slow. And I thought this through, and came to the conclusion that BT is inherently faster. Below is the reasoning for this:

For the sake of argument, let's say that the distro bots are all EDU bots, so I2 users effectively don't count into time costs, and can pump out 300kb/s to the world. For an average release for a moderately popular show, let's say 800 leechers in the initial 2 hours. And as a simple number, the file being distributed is 150,000KB.

Scenario 1: direct to BitTorrent, where the encoder has, say, residential broadband
The encoder can consistently put out 15kb/s seeding the torrent. All leechers are thus limited to 15kb/s, and leechers hitting the torrent during initial seeding will on average require 5000 seconds which is slightly more than 1.5 hours. Total time: 1.5h to first leecher copy. And because it's BitTorrent, and there's going to be a high-upload leecher on the torrent that can redistribute data faster than the encoder can send new data, within 2h about 25% of the leechers after announce have the file. So 200 copies are out after 2h.

Scenario 2: encoder has residential broadband, distro to the bots in IRC
The encoder remains limited to 15kb/s to the bots = 1.5h. The bots themselves are on I2 so it'll take a few minutes (minor) to get all the bots loaded. Then the public release, and again I2 users are basically done... let's say 10% of leechers were I2. Each of the (say) 5 bots can pump out 300kb/s, so on average every 8 minutes 5 people will complete the file. Let's also add 30 fserves on I2, capped to 30kb/s upload (for good measure), so every 84 minutes an additional 30 users can get the file, yielding 72 distributed copies every 84 minutes, or 1h40m to get 120 copies outside of I2. Total time from encoder to 200 copies worldwide = 1.5h + 1.6h = 3.1h.

Scenario 3: encoder is on I2, I2 users are rate-capped to 30kb/s average, BitTorrent distro, 5 bots
The encoder takes no time to get the file seeded to the bots and I2 users. Total seeding upload capacity now is 3.9MB/s to the world, so to transmit the entire file to the torrent in the world would take about 40 seconds. Leechers are probably going to be limited to their own downstream cap, which is somewhere around 1MB/s at most, and around 400KB/s on average, so 6.25 minutes to worldwide distro.

Scenario 4: encoder is on I2, I2 users are rate-capped to 30kb/s average, BitTorrent distro, no bots
Again, we start with this massive initial upload capacity with the power of 80 I2 users. Losing the bots decreased the upload capacity to 2.4MB/s, still much higher than most downstream providers will grant. So again, 6.25 minutes to worldwide distro.

Scenario 5: encoder is on I2, 30 fservs on I2 (these numbers get worse if they aren't), 5 bots, IRC distro
Like above IRC distro (scenario 2), but without the silly 1.5h to get the file from the encoder to the bots. So 1.6h to get 200 copies out.

Conclusion: IRC is slower than BT on average; BitTorrent can get large numbers of distributed copies out much much faster than IRC distro. The reason? Because there's going to be a larger upload bandwidth available, since leechers must also upload with BT, and that BT removes the cost of an encoder uploading to the bots in distro.

I am only on residential broadband, btw, so it's rather obvious that BT is the way to go when I distro.

Why this matters to fansub groups: new groups that think IRC distro is sufficient, they're right. But it's not as fast. It is NOT necessary to recruit IRC distro at all - there'll be a fast uploader on the torrent for you in most cases.

[CompShrink]

Bittorrent basically gets it to more people, but slower to each person. There is no waiting in queues like irc, so you get a constant speed, so it LOOKS slower than waiting, and then getting really fast speed.

Bittorrent is more effective, but to each individual, it may not look like it is.

[Forse]

Well okey let's say u seed on BT and all is well. 1 year passes and the series is still not licensed (it happens a lot). Some1 wants to download some episode...are u sure he will get good speeds then? Usually seed number drops to 0 in 4 weeks. BT is great when you distro file that everyone wants, but it's really bad for long term distro.

IRC is here to stay and it's still best way to find rare/not popular anime period.

[ZhouYu]

bt is good... but only good if there be people who actually seeds... instead of just leeching and cappin uploads to 3kb/s

[ElNipp]

Originally Posted by lavalyn

Scenario 1: direct to BitTorrent, where the encoder has, say, residential broadband
The encoder can consistently put out 15kb/s seeding the torrent. All leechers are thus limited to 15kb/s, and leechers hitting the torrent during initial seeding will on average require 5000 seconds which is slightly more than 1.5 hours. Total time: 1.5h to first leecher copy. And because it's BitTorrent, and there's going to be a high-upload leecher on the torrent that can redistribute data faster than the encoder can send new data, within 2h about 25% of the leechers after announce have the file. So 200 copies are out after 2h.

I'm not going to argue about the pros and cons of BT/IRC distro, but you've a little mistake in your calculation. It takes 10000 seconds to upload 150,000kb at 15kb/s, not 5000. The first copy will be complete after about 2h45min - 3h.

Same for Scenario 2 too of course.

[scotty81]

I like BT because I have a slow connection (dsl 128 ) but it's true I only use it in the first week of a release! afterwards, it's useless, people either cut their upload with azureus or whatever, or shut their BT client as soon as finished! people don't like to keep seeding! they just download for their own!
I remember the first BT clients where you couldn't cut the upload, that was sharing!

[MrMonkey]

Originally Posted by scotty81

I like BT because I have a slow connection (dsl 128 ) but it's true I only use it in the first week of a release! afterwards, it's useless, people either cut their upload with azureus or whatever, or shut their BT client as soon as finished! people don't like to keep seeding! they just download for their own!
I remember the first BT clients where you couldn't cut the upload, that was sharing!

The thing I like about BT, is that leechers HAVE to upload something, whereas they dont with IRC. Even if someone stops seeding right after the download completes, they've still uploaded more than if they got the file from IRC.

As for speed, it depends on your connection whether it matters or not. Someone on a 512 DSL line isnt going to see a difference between IRC and BT, whereas people with faster connections might. Personally I think the people with faster connections should use BT more, since they usually have more upload BW than slower people and help the network more. But I guess some people are really anal about getting "file X" in 10 seconds or whatever.

[scotty81]

well for upload, with a 128dsl connection you have the same upload as a 512dsl connection!
it is true BT forces every body to share, but I heard of new clients for BT such as Azureus that allow you to cut your upload!
the main problem with BT is that , as said up in this topic, the seeding is for a short period!!

[MrMonkey]

Originally Posted by scotty81

well for upload, with a 128dsl connection you have the same upload as a 512dsl connection!
it is true BT forces every body to share, but I heard of new clients for BT such as Azureus that allow you to cut your upload!
the main problem with BT is that , as said up in this topic, the seeding is for a short period!!

Clients such as azureus allow you to adjust your upload bandwidth. Its mainly for people like you and me with slower connections, so that they still have enough bandwidth to browse the web and etc.

BT works on a "tit-for-tat" system, meaning the more you upload, the faster your download will be (its proportional, not exact), so if people did cut thier upload to 0, they'd either be downloading incredibly slowly, or not at all.

On the whole most people dont cut their uploads, or those that do do so for a reason, not just because they dont want to share. There are always bad apples, but that can't be helped.

[lavalyn]

Originally Posted by MrMonkey

BT works on a "tit-for-tat" system, meaning the more you upload, the faster your download will be (its proportional, not exact), so if people did cut thier upload to 0, they'd either be downloading incredibly slowly, or not at all.

Not exactly true, but that's the end effect.

BT clients favor sending to uploaders. This is determined by the upload speed your client observes... which does mean that a very fast uploader that uploads to 40 others at once will nonetheless not get a particularly good download speed. It also means that people that tend to not upload will not be particularly favored.

Otherwise, a person could hack the source and claim to have uploaded lots, and trick other clients. This doesn't work, since upload targets are determined by the uploader, not the downloader.

Superseed clients now take this one step further, by watching over all clients and observing the time to upload the sent piece. Since superseeds only send each part once, it is immediately identifiable when (and thus how long it took) a given client has completed a part upload to another.

[warnold]

Let me just throw my summary into the ring:

If you devote the same upload bandwith to IRC or BT, BT will on average be faster, since it also adds in the available upload bandwith of all the leechers.

Very few groups do this. Most have many Mb/s available upload on their IRC bots/fservs/etc and 1 slow uploader for BT. Then they say that BT is slow.

--
-billy-

[lomeando]

The main problem with keeping old releases seeded is that there are simply too many of them, while BitTorrent is a one-file-at-a-time (or one batch of files, but essentially the same thing). People aren't willing to run 10 instances of the client to keep a 52 episode series in 5 episode batches seeded.

phaze (of Soldats) has written a simple SmartSeeder script (http://phaze.soldats.net) that will rotate seeds to the files that need them. This works very well... you can designate some uploading bandwidth, much like XDCC bots do, and it periodically changes the file it is seeding with that bandwidth. You don't suffer the performance hit (mostly due to memory usage) associated with running a bajillion clients, but you keep good coverage of older releases.

This works much like the queue system, except that
1) The file to upload is chosen by the demand for it, instead of by what's next in the queue.

This could be both good and bad. It's potentially possible to starve a given file, but files with no seeds at all are alwas preferred over those that have them, and as it is uploaded it a) loses downloaders (and thus demand) and probably b) gains seeds. I haven't observed any starvation in practice.

The reason it's good depends on
2) Once a file is well-seeded again, it moves on to seed something else and lets the people it already gave the file to finish off the distribution. Thus if you want an uncommon file, you don't have to sit behind 30 people all waiting to download the same thing. If you want a common file, then it is well seeded.

More groups should use this. Right now Soldats and Anime-Kissaten are the only ones I know of that do. It makes getting old releases from them much easier.

[Access]

Originally Posted by scotty81

well for upload, with a 128dsl connection you have the same upload as a 512dsl connection!
it is true BT forces every body to share, but I heard of new clients for BT such as Azureus that allow you to cut your upload!
the main problem with BT is that , as said up in this topic, the seeding is for a short period!!

Yes you can cut your own upload to nothing, but this means that you'll be at the bottom of the queue as far as downloading too. What really hurts IMO is the clients that close as soon as they finish the file and never become seeds.

I think people are forgetting that BT is a timesaver because you don't have to queue or actively do anything to get a release. You just run the torrent and let it complete on it's own. Before you had to go find the IRC channel, hope the channel itself wasn't full, find an FServ whose Queue was not full, navigate the particular fserve and find the download on the fserve and queue up a download, make sure you don't get disconnected from the channel before the download starts, and then check your download with a .csv when it's done. This made keeping up with everything a real pain. BT is much easier to use and trouble-free, it doesn't require any kind of 'active management'.

The only reason who don't like BT are traders who suffer now b'cos everyone can easily get every current release or the people with fast upload connections who were in demand at one time for getting releases out quickly but no longer are. Having a fast BT seed or two is still a good thing but it's not as visible and doesn't get you the respect it used to.

[CompShrink]

BTW, as for fast connections, I have gotten 900kbps on a BT before, and my max download is around 1200kbps... I was also uploading at 800kbps mind you... but the point is it isn't slower for high speed users, unless it's a really unpopular series. In that case, on IRC, it would probably only be on a slow host anyway, and it wouldn't be fast regardless.

Some programs, like azurues I believe, don't open seperate clients for each file, so seeding lots of files isn't that processor intensive... and with almost every new release they get more efficient at using less cpu cycles.

The rare things often aren't seeded on BT, that's true. It's alot easier for the uploader to leave all the anime on his hard drive in an fserve on irc than to keep seeding all the stuff on his hard drive. Thus, there is an advantage to irc. Not to mention chating can be nice... imagine that, using IRC to chat. :P

[Shii]

That's nothing, I sometimes get 2,400 kbps on a BT...



which is 300 kBps, of course...

[complich8]

Originally Posted by ashibaka

That's nothing, I sometimes get 2,400 kbps on a BT...


which is 300 kBps, of course...

my peak down on bt was 7 MB/sec down.... but the only clients on the torrent were two computers separated by a 100 mbit switch and using a local tracker. I think that was about the limit of the old less-efficient bittorrent on those machines though ....
compared to irc dcc's (peaked out at about 9 MB/sec) or ftp transfers (11 MB/sec) it's not too great, but then with all the sha calculations it had to do and the whole nonlinear and interrupted read/write thing, I could understand it being a bit slower than unchecked downloads.

the fastest uploading seed I've seen screenshots of was hit by a friend of mine while he was in a campus lab earlier this year. He downloaded the file at about 1.5 MB/sec and seeded it with 400 sends and unlimited send speed, and some command line tweaks .... pushed out about 6.5 MB/sec to the torrent for a solid 3 hours before he had to leave. That was for one of those aone torrents, I think a naruto episode or something but not sure anymore. He's probably got a screenshot of it lying around if anyone wants to see .

The big prob with bt is that a lot of the multiple megs/sec of bandwidth that people can get with their xdcc bots they can't get with bt, because they don't have python, or don't have a shell, or don't have a gui, or because the machines they're wanting to use can't handle the memory demands that bt's implementation places on them (or has placed on them in the past). If everyone were to devote their bandwidth to bittorrent, it'd be great for people using it, 'cause there'd be lots of completion and everyone would be happy.... but not everyone can use bittorrent, just like not everyone can use irc and not everyone can use dc and not everyone can use ftp. Diversification is NOT a bad thing, but deciding to rule out options because other options exist to solve similar problems better IS bad.

[Umbrae]

BT just makes me hate my ISP. I have 3 MB download but only a 128K up. the fastest down I have ever seen is 125kbps.

Even though I prefer BT to IRC for recent downloads. although for older files, IRC still seems to be the way to go 48+ hour downloads are not much fun.

[CompShrink]

Yes, ashibaka, I was talking about 900kBps...

I think anyone on this forum would tend to agree BT is good, since it's a site about BT.

[Anax]

I use Azureus to download and seed, and keep pretty much everything I currently have in the download list, set up to auto-reseed if necessary. This works pretty well, although I do tend to hand-tweak things to cut down on chatter when I'm downloading an episode, or to force a really poor torrent to get seeded immediately. It's my hope that Azureus will get better support for this kind of behavior. (It always chooses the "first" torrent that needs seeding to start next, and having 70+ torrents in the list also makes things complicated.)

I do think it's unfortunate when I see some older (and even not that much older) series go un-seeded. I think that with modern multi-torrent clients, more people should be able to keep seeding more low-profile items for a longer period. If you're looking for something a year or more in the past, a slow download is better than no download at all.

[acefighter]

Considering that my group uses only BitTorrent for distribution, and no fserves, I occasionally get requests to open an IRC channel for faster distro and such. We personally like BitTorrent but other groups swear by it, that's fine.

But the most common complaint with BT is that it's slow. And I thought this through, and came to the conclusion that BT is inherently faster. Below is the reasoning for this:

For the sake of argument, let's say that the distro bots are all EDU bots, so I2 users effectively don't count into time costs, and can pump out 300kb/s to the world. For an average release for a moderately popular show, let's say 800 leechers in the initial 2 hours. And as a simple number, the file being distributed is 150,000KB.

Scenario 1: direct to BitTorrent, where the encoder has, say, residential broadband
The encoder can consistently put out 15kb/s seeding the torrent. All leechers are thus limited to 15kb/s, and leechers hitting the torrent during initial seeding will on average require 5000 seconds which is slightly more than 1.5 hours. Total time: 1.5h to first leecher copy. And because it's BitTorrent, and there's going to be a high-upload leecher on the torrent that can redistribute data faster than the encoder can send new data, within 2h about 25% of the leechers after announce have the file. So 200 copies are out after 2h.

Scenario 2: encoder has residential broadband, distro to the bots in IRC
The encoder remains limited to 15kb/s to the bots = 1.5h. The bots themselves are on I2 so it'll take a few minutes (minor) to get all the bots loaded. Then the public release, and again I2 users are basically done... let's say 10% of leechers were I2. Each of the (say) 5 bots can pump out 300kb/s, so on average every 8 minutes 5 people will complete the file. Let's also add 30 fserves on I2, capped to 30kb/s upload (for good measure), so every 84 minutes an additional 30 users can get the file, yielding 72 distributed copies every 84 minutes, or 1h40m to get 120 copies outside of I2. Total time from encoder to 200 copies worldwide = 1.5h + 1.6h = 3.1h.

Scenario 3: encoder is on I2, I2 users are rate-capped to 30kb/s average, BitTorrent distro, 5 bots
The encoder takes no time to get the file seeded to the bots and I2 users. Total seeding upload capacity now is 3.9MB/s to the world, so to transmit the entire file to the torrent in the world would take about 40 seconds. Leechers are probably going to be limited to their own downstream cap, which is somewhere around 1MB/s at most, and around 400KB/s on average, so 6.25 minutes to worldwide distro.

Scenario 4: encoder is on I2, I2 users are rate-capped to 30kb/s average, BitTorrent distro, no bots
Again, we start with this massive initial upload capacity with the power of 80 I2 users. Losing the bots decreased the upload capacity to 2.4MB/s, still much higher than most downstream providers will grant. So again, 6.25 minutes to worldwide distro.

Scenario 5: encoder is on I2, 30 fservs on I2 (these numbers get worse if they aren't), 5 bots, IRC distro
Like above IRC distro (scenario 2), but without the silly 1.5h to get the file from the encoder to the bots. So 1.6h to get 200 copies out.

Conclusion: IRC is slower than BT on average; BitTorrent can get large numbers of distributed copies out much much faster than IRC distro. The reason? Because there's going to be a larger upload bandwidth available, since leechers must also upload with BT, and that BT removes the cost of an encoder uploading to the bots in distro.

I am only on residential broadband, btw, so it's rather obvious that BT is the way to go when I distro.

Why this matters to fansub groups: new groups that think IRC distro is sufficient, they're right. But it's not as fast. It is NOT necessary to recruit IRC distro at all - there'll be a fast uploader on the torrent for you in most cases
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i love these whiny ass people. this is for that noob.(mirc is used more than bitorrent. about all fansubs have mirc while only bigger ones actually do bittorrent. the only reason why they look like thier so many is because this place only supports bt fansubbs. if you do not have bittorrent you will not be really acknowledge here.

if you want proof go to baka-updates.com Thier data base is about 20x bigger than here.

second bittorrent is faster for me and bet you for many others. i normally get a constant speed of about 75-150kbps. mirc takes about a freakin hour just to get in line to dl from a good server than another hour of waiting.. even thought it sometimes goes faster its not nearly as efficent.

also on the other people. dam wtf is wrong with your computers. 125kbps is nto that fast. also what takes 48 hours to dl. i dl 6 gigs on bt before and it was only 34 hours i believe and that was from a slow server.

thrid before you do not think i do not seed. i do i just do not seed full until download is completed