qBittorrent official forums

it seems qbittorrent connects to a lot less peers or none at all while seeding a torrent compared to utorrent. ports are forwarded properly and working, even disabled the firewall to be sure is not a problem there. Yet for a given torrent (private tracker) when seeding with qbittorrent even if it reports 100+ peers none connects . At the same time i tried seeding same torrent with utorrent  and it actually gets connected to some peers and seeds.

Running on windows 10 v3.3.14, as i said port forwarded and working, firewall disabled, prefer encryption, outgoing ports enabled (also tried with disabled - same behavior) .

Any advice is greatly appreciated

Later edit:
Upon further inspection it seem the uTP peers are the issue, even if one tries to connect it disappears seconds late. Yes uTP protocol is enabled un Settings - Speed

Some uTP peers stay connected in qBitTorrent for me, however most do disconnect.
I have seen major issues with qBT trying to upload to uTorrent using uTP -- it seems to be slow and buggy and probably why the disconnects happen.

uTorrent definitely seems to connect to more peers, even TCP peers.

Thanks for confirming Switeck. I did more research looks like libtorrent is to blame for this behavior.

Anyway I'm willing to try any ideas that might resolve the issue at least partially.
Right now I download with qBT and upload with uT where I need to make ratio fast. Not the best solution

Problems qBT still has:
1.limited to 1 CPU core - https://github.com/xlgjjff/libtorrent/issues/552
2.poor multi-tracker support - index.php/topic,71.msg23501.html#msg23501
3.misaligned multi-file torrents cause slow speeds - index.php/topic,2627.msg12725.html#msg12725
4.neither preallocate files nor sparse files works well - index.php/topic,3787.0.html  and    index.php/topic,3787.msg19159.html#msg19159    and http://forum.deluge-torrent.org/viewtopic.php?t=27725
5.sparse file handling causes horrific file fragmentation - index.php/topic,3743.msg19531.html#msg19531    and    https://github.com/qbittorrent/qBittorr ... /4124  qBittorrent performs horribly wrong disk I/O
6.setting a really large cache still causes crashes - index.php/topic,3567.msg17758.html#msg17758
7.Torrents won't seed unless "Global maximum number of connections" is enabled - https://github.com/qbittorrent/qBittorrent/issues/4617
8.UPnP port mapping is buggy - https://github.com/qbittorrent/qBittorrent/issues/5695 Old UPnP forwarded ports are not removed from router when QBT is upgraded to a new version.
9.qBittorrent is extremely slow to close (and can corrupt/lose its settings and torrents if shut down using task manager!) - https://github.com/qbittorrent/qBittorrent/issues/5662
10.Not connecting to some peers - https://github.com/qbittorrent/qBittorrent/issues/7155

I'd suggest using uTorrent entirely instead until these problems are fixed.

uTorrent has serious caching problems with large files and high speed internet connection.  With uTorrent I get diskoverload on 10gb+ torrents even on ssd on a gbit connection. uTorrent only works ok for connections upto 150 mbps . This was ok 5 years ago but it seems they are stuck in time and not doing anything about if it

Are you using sparse files with uTorrent? (...on a NTFS formatted drive no doubt if sparse is even available.)
Although nowhere near as crazy as qBT/Deluge (libtorrent). uT too shares higher fragmentation levels with sparse files than using preallocate. There's an option to not zero fill files, but it doesn't work with NTFS and requires admin-level (or higher!) access to the drive/s.

Misaligned multi-file torrents are also rough on uTorrent's max speeds.

uTorrent can seed crazy-fast (over 100 MB/sec), as can too qBT and Deluge...but only under special testing conditions:
index.php/topic,3956.0.html
EXTREME Speed Tests of various BitTorrent Apps (over loopback/ Windows)

no sparse files no preallocation . in real life for the same torrent on the same hard disk, utorrent (both 2.2.1 and latest version) are stuck in disk overloaded more often than not averaging a download speed of 25 mB/s while qbittorrent for all it's faults pulls an average of 75 mB/s . thats 3 times more speed on the same torrent and same hardware. True the results are closer for a torrent of 1-2 gB since utorrent barely fills it's cache there, but on larger files there is no discussion that uT no matter how you configurate it has real issues when writing to hdd. On SSD with utorrent, unsurprisingly at 80mB/s  disk gets overloaded. all in all, 5 years ago when internet speeds and downloads were considerably smaller utorrent was doing a good job, now it doesn't and i think it's developers are on ADSL lines otherwise i can't understand how they can leave it like this.

Regarding qBT i hope someone from the development team sees this and tries to address the uTP protocol, at this point im not even sure where the problem is: qbt implementation of libtorrent or libtorrent itself but im pretty sure it affects all platforms.

When I posted here I thought there was a misconfiguration on my side, but the more i researched is a general problem which due ignorance i haven't spotted before

Is qBT downloading to the same SSD at 75 MB/sec that uTorrent can get to 80 MB/sec but then has horrible disk overloads?

On ssd qBT goes full bandwidth which in my case is 116 mB/s and stays there for all the period of the download

Ut gets to about 80 mB/s cache is full and starts overloading and keeps overloading on and off till completes the download.(on ssd)

On a HDD with a large file torrent uT fills it's max ram cache of 1.8 gb pretty quick and overloads continuously till it eventually finishes the download

Again this all depends on the torrent. If it's a 1 gb TV show episode all is good. If it's a 40 GB Blu-ray ISO then uTorrent is to be avoided if you have high speed connection and a healthy pool

Anyway we went with the discoussion beyond the purpose of this thread

But it's pretty hard to get 116 MB/sec download speeds in qBT unless there's other gbit/sec class peers and seeds and/or LOTS of peers+seeds.

...And if there's problems while seeding, the same problems may show up to a lesser extent while downloading.

Now if it's private trackers...many are horribly broken and give out random ips on a torrent even if only 1 is a peer.
So a seed gets a big list of other seed ips on tracker update as though that's somehow useful to it.
uTorrent will hammer through those ips pretty quickly via uTP, but qBitTorrent will typically take longer either because it's trying both in sequence with cooldowns and/or because its uTP attempts are possibly botched in some way. (Both will resemble an outgoing DoS attack while doing it.)

yes there are a lots of gbit seeders as well. and while yes it may happen when downloading as well, it likely you wont notice given that there are a lots of seeds (2k+). But after becoming a seeder is pretty useful to be connected to more peers since the competition is high (2k+ seeders/ 100 leechers ) and this where uTP helps a lot utorrent compared to qbt.