Slow upload speed, can't figure why

[dama]

Hi

I have been using qBittorrent for few years now and was always able to utilize upload speed to the max. Since the last update or past few weeks I'm achieving only 50% (which is 6Mb/s) of upload limit. At first I thought maybe there are not enough peers or maybe they have slow connection but after few days of inspecting the situation I became suspicious. So I started looking at options, turning things of and on, changing values, installing older versions (4.3.7, 4.3.6, 4.3.5) and upload speed would always stay the same around 6Mb/s with limit set to 12MB/s.

Here are my current settings:






Can somebody please tell why is this happening and how to fix it because I have been through dozen of articles and forum post on Google and nothing helps.

Regards

[Switeck]

On the 1st picture, you told qBitTorrent to connect to as many as 50 peers per torrent...then only upload to 5 of those at once. The other 45 connected peers will get nothing most of the time.
With the speed of your upload, you could probably set upload slots per torrent higher and reduce max connections per torrent.
If you have no downloading torrents, you could lower max connections per torrent to barely higher than max upload slots per torrent.
This issue is described better here:
https://github.com/qbittorrent/qBittorrent/issues/2193

You may also want to set a global maximum upload slot limit somewhat less than global connection max, like 400 total of the 500 connections. That should work out to be about 30 KiloBYTES/second average speed per upload slot if all were in use at once.


Enable anonymous mode is checked in 3rd picture (qBT's BitTorrent section of Options)...it can cripple speeds by disabling a lot of qBT's features -- even if they are enabled elsewhere!
...And it won't make qBitTorrent actually anonymous, it's a poorly-named feature.


4th picture, advanced settings...
If you are getting 100's of peer connections at a time, probably best to disable:
Resolve peer countries
Download tracker's favicon

Increase Disk cache expiry interval from 60 seconds (1 minute) to 1000 seconds or more. That should help keep pieces of torrents in ram instead of constantly re-fetching them from the drive after 1 minute of non-use.
Try checking Enable OS cache...but WARNING this can eat a LOT of ram!


5th picture, more advanced settings...
Check "Send upload piece suggestions"
(This should tell peers to download more pieces in sequential chunks which can be slightly quicker than downloading pieces in random order.)

[dama]

Hi Switeck and thanks for helping out.

Here is what I did under connection options:


Since I am seeding 95% of the time, and currently there are 90 torrents in client, these settings should be fine, I guess. I'm saying this because torrents I seed are not that popular and have at most 5 peers connected, very rarely more than 10.

I did all other suggestions like you said and set Disk cache expiry interval to 1200s but unfortunately nothing changed, upload speed is dancing around 6MB/s:


Something is choking my upload and I doubt changing options will resolve it, just a gut feeling, because at one point few months ago I had around 120 torrents with the same setting as in the first post and I had no problem with upload speed, it was at max all the time. I used to upload about 450-500GB per day and now I barely reach 250GB. Kind of frustrating but never the less I'm willing to try to fix it.

In few places I read that Asynchronous I/O threads option could be the cause of the problem but I haven't seen any difference changing it from, 10 to 4, then to 6, and in the end back to 10. Do you have any opinion about it?

[Switeck]

"torrents I seed are not that popular and have at most 5 peers connected, very rarely more than 10."

So that means more-or-less every peer that joins one of your torrents should be getting uploaded to by your qBitTorrent client.
Try checking on one of the busy torrents that most peers are being upload to.

"I read that Asynchronous I/O threads option could be the cause of the problem but I haven't seen any difference changing it from, 10 to 4, then to 6, and in the end back to 10. Do you have any opinion about it?"

That value is best left at 4 or lower if you don't have at least a quad core CPU.
8 if you have a quad-core, maybe 16 if higher.

is the switch at the middle bottom of the qBitTorrent window turned to the left or right side?
(It sets speeds to alternate or normal values.)

[dama]

That value is best left at 4 or lower if you don't have at least a quad core CPU.
8 if you have a quad-core, maybe 16 if higher.

OK, now it is set to 4 but I am not seeing any difference in upload speed.

is the switch at the middle bottom of the qBitTorrent window turned to the left or right side?

It is turned to the right:


Switeck, as much as I see this problem cannot be solved by changing options as many other users are complaining viewtopic.php?f=14&t=9555 and not getting anywhere. It looks to me problem lies somewhere "deeper" inside qBitTorrent. I want to thank you for your time and will to help me out but I think it is the best to wait out for new version and hope it will be addressed and fixed.

Kind regards

[Switeck]

If you want to look deeper inside qBitTorrent, you'd have to try with a fresh set of settings for it and/or different torrents.

But upload speed is always a tricky one, because you can't count on other peers being where you want them when you want them.
In a private tracker, they can be overloaded by a swarm of fast seeds feeding them all at the same time.
On public torrents, often they're not able to download fast from you for other reasons.
I have trouble filling my barely 1 MB/s upload most of the time.

My hunch says try another BitTorrent client...but don't be shocked if you get similar upload speed results.
I've seen ISPs in the past put unexpected limitations on customer connections without warning.
Could even be indirectly due to some peering war going on at exchanges around the world.

There's also an active campaign to particularly discredit and indirectly ban BitTorrent clients, file sharing, and even open source software in general.

[dama]

By "fresh set of settings for it" do you mean only deleting files in C:\Users\<username>\AppData\Roaming\qBittorrent?
Do I also have to reinstall qBitTorrent?

To preserve torrents and share ratios do I need to keep only C:\Users\<username>\AppData\Local\qBittorrent\BT_backup folder or whole parent folder C:\Users\<username>\AppData\Local\qBittorrent is required?

[Switeck]

You can keep all the resume files and you don't have to reinstall qBitTorrent.
Only qBT's settings files need to be replaced and those are found in...

https://github.com/qbittorrent/qBittorr ... s_settings

Something like this:
C:\Documents and Settings\<username>\AppData\Roaming\qBittorrent
for settings files.

Doesn't hurt to back up the settings AND resume files before mucking around like this, as I can painfully attest!
If qBitTorrent crashes, it may recheck every torrent loaded into it...and if you have >100 GB of torrents, that can take hours to days!

I've seen qBitTorrent not connect to as many active peers as uTorrent on the same torrent. (by trying on the same port 1-at-a-time and even using different computers and different internet connections at the same time, even having them PEX with each other.) I'm still unsure as to the cause.

qBitTorrent also has speed problems with uTP connections. They often won't run faster than ~800 KB/sec per peer connection even on a LAN or local loopback (2 BitTorent clients on same PC connected to each other directly)...and typically slower over the internet even with far faster connections on both ends. The head libtorrent developer is still at a complete loss as to why:
https://github.com/arvidn/libtorrent/is ... -784974114

...BUT! If you have 10+ uTP active peers connected at once then you should still be able to upload at >5 MB/sec, (500 KB/sec each) assuming those peers are mostly on decent broadband connections.

The slow upload speeds I have can be blamed on very few peers on the many torrents I have "active" -- only about 1 out of 100 has even a single peer and 1 out of 1000+ might have 2 peers.

[dama]

Hi
was a bit busy but here is what I did in last few days:

4 days ago I reinstalled qBittorrent and checked the box to remove settings and here is the speed graph from that day:

As you can see after fresh install upload speed was ideal for about 2.5h and then sudden drop for who knows what reason after which it never recovered.

And here are the speed graphs from last three days:




They are very similar in a sense that upload is slowly "stabilizing" over time and it reaches the limit over many hours.
Don't know what is causing this behaviour but it is much better then previous, around 6MB/s max.

I am pretty sure that I can upload at max speed all the time like those first 2.5h from first speed graph but something is "choking" or preventing it from happening. And I highly doubt that number of peers or their download capabilities are the reason behind it. Could it be my PC?

Anyway current situation after reinstall is much more acceptable and doubt I will be changing anything any more.
So for others reading maybe reinstalling qBittorrent and deleting setting (backup them before) might help, like Switeck suggested.

Regards

[Nero]

I have a similar problem regarding the slow upload speeds.

Installed the client today for the first time (default settings), downloads are working fine, but I've online uploaded around 82 MiB after several hours of seeding. I've tried fiddling with the settings a bit to increase upload slots and such, but it doesn't really seem to make much of a differece.

If this is an issue with the client than over time it will hurt the community (more qb users = less uploads).