Slow download speeds in 2.00.

[Rolcol]

After experiencing this today and seeing this ticket, I've taken livings' advice and started this discussion thread.

This originated after a fix for ticket #2993. In changeset r10332 jordan included a new throttle. In that same ticket, a few users and I reported slower download speeds in new torrents. The problem isn't that there aren't enough peers. Simply switching to Transmission v1.93 boosts the speed of download. For the recent torrent I had problems with, I boosted the amount of peers to 500 as a way to see if the bigger pool would bring better peers. The client connected to roughly 400 peers with 0 stated as downloading from.

This isn't a problem in all torrents. I've had very good and consistant speeds in well seeded and older torrents. I probably got lucky after the last commit by jordan and erroneously said the problem was gone.

Tested in stable version 2.00 on OSX 10.6.4, GTK+ interface on Ubuntu 10.04, and transmission-daemon on Ubuntu 10.04.

Other users that have noticed this:
superfly_by
fbellomi
lazybones

[lazybones]

You know what. I just remembered they switched to si KiB units
That might account for some of it, but speeds are still poor and now even harder to calculate as there isn't a damn network service sold that uses KiB it's only use is in os hd sizes.

[Rolcol]

You know what. I just remembered they switched to si KiB units
That might account for some of it, but speeds are still poor and now even harder to calculate as there isn't a damn network service sold that uses KiB it's only use is in os hd sizes.

It's always been like that. The units just changed to better fit what was reported.

[lazybones]

Managed to get some very good speeds on another torrent with lots of peers.

Consistancy is near impossible with torrents. It is possible the two downloads I had at the time of upgrade where just poor examples.

[Fiete5401]

I have the same problem as Rolcol.
2.0 seems to start seeding very fast but when it comes to downloading 2.0 finds a lot peers but doesn't start downloading from them. I went the same way Rolcol went by raising the amount of peers per torrent without any success.

Yesterday I tried the exact same torrent in 2,0, 1.93 and utorrent 1.0 beta.
2.0 download speed: 0-3 KB/s but mostly flat zero
1.93 download speed: 3-10 KB/s
Utorrent 1.0 beta: 15-30 KB/s

2.0 has a serious problem connecting to peers willing to seed. The peers are all there but TM is currently not able to make use of them. And yes this does not occur on every torrent.
I'm living in a rural area and have a 115 KB/s down // 14 KB/s up line.

I'm running Mac OS X 10.6.4.

EDIT: 10820 -> flat zero.

[Zyxmon]

I had slow download speeds with transmission 2.00b2 and 2.00b1 on my NAS with Marvel Kirkwood 88F6281 ARM cpu compared with 1.93.
Before installing version 2.0 I have edited settings.json - reduced peer-limit-per-torrent and upload-slots-per-torrent. Now the download speed is OK.

[fbellomi]

Consistancy is near impossible with torrents. It is possible the two downloads I had at the time of upgrade where just poor examples.

I have to say that my results seem very consistent in being slower with 2.0.
I have installed 1.93 alongside with 2.0; with some torrents with many seeds, 1.93 downloads 300 KB/s (my download limit), where 2.00 has a very slow starts, and seems to remain at 50 KB/s.

My internet connection has a very asymmetric upload/download bandwidth: download bandwidth is around 400 KB/s (I limit Trasmission at 300), upload bandwidth is around 40 (i limit Transmission at 20). I wonder if this can somewhat confuse the optimization algorithm.

Francesco

[Zyxmon]

fbellomi
My ADSL connection is also asymmetric. The limits in transmission are set to 400/60. After fixing settings.json I can download at 400KB/c. Before it was 400 with 1.93 and lower 200 with 2.0.
In fact my connection cannot hold 400/60 simultaneously because of SYN/ASK packets. Nevertheless I have now 400RB/s download with 20-40KB/s upload. When download ends my upload goes to 60.

[gunzip]

so far i'm not seeing slower speeds with 2.00. just ran a couple tests on a well-seeded torrent comparing Transmission 2.00 with rTorrent 0.8.6 and both gave comparable speeds:

Transmission 2.00 Download Time: 12mn 10sec
rTorrent 0.8.6 Download Time: 11mn 39sec

i used same torrent with file size 175 MB. yes rTorrent was about 30 seconds faster but that's only 4% and not really significant. in both cases i limit connect peers to 90, upload slots to 12, and limit upload rate to 80% of max.

My OS is Debian Linux.

[ent1234]

Same problem, and highly repeatable, using Mac OS X SnowLeopard 10.6.2.

I switched to v2.00 (10766), and although I had "connected" to over 110 peers, my download speed was almost always 0 KB/s, with occasional jumps to 10-20 KB/s which rarely lasted more than 1 minute. Over 2 days the 50GB torrent downloaded less than 20MB of files.

I switched back to v1.93 (10621), and "connected" again to over 110 peers, my download speed immediately averaged between 500KB/s to 1.5MB/s.

Back to v2.0, back to 0 KB/s. Restarted Transmission, got a few more KB/s before dropping back to 0 again. Left if for a couple hours and got almost nothing downloaded.

Back to v1.93, back to over 800KB/s, and the 50GB torrent downloaded over the next few days.

The 50GB torrent was posted 3/27/2006: (129 seeders, 1210 leechers)

The smaller torrents with fewer peers (9 of 9) wouldn't download anything using v2.0, but switching back to v1.93, they downloaded slowly but consistently.

Uploading worked fine with both versions. v2.00 would max out any upload speed I set for it (anywhere from 10-40KB/s), but rarely would it download anything from those peers, even when they had nearly the entire torrent available.

[Headcase_Fargone]

Seeing the same thing here. I have a NAS running 1.93 and an actual desktop running 2.00. I set the same two torrents on both and 1.93 was much faster. Different machines I know, but honestly the desktop should be faster as it has infinitely more resources than that little NAS.

[Thinine]

I'm experiencing the same thing with 2.00 on 10.6.4. I thought the problem might have been my router, but after messing with the port forwarding for a while I found this thread. So it definitely looks like it's a 2.00 issue, since going back to 1.93 has brought the speeds back up to normal.

[lazybones]

I have been watching my torrent speeds over the last week and it seems that torrents with BIG swarms often perform well as they should however when the number of peers is lower around 100 seeds / peers transmissions seems to really struggle to download at all.. I haven't tried reverting my NAS to 93 but before these smaller swarms would just perform slowly but not this poorly...

[Jordan]

So, how about 2.01?

[lazybones]

So, how about 2.01?

Waiting on an optware release for my NAS.. Normally it comes out a bout a week later... sometimes a little sooner in the unstable repo... I will keep an eye out.