qBittorrent downloading at less than 20 MB/s with 2.5 Gbps connection

[vickdini]

qBittorrent & operating system versions

qBittorrent: 4.5.2
Operating system: Raspbian: Linux 6.1.0-rpi7-rpi-v8 #1 SMP PREEMPT Debian 1:6.1.63-1+rpt1 (2023-11-24) aarch64 GNU/Linux
Libtorrent: | 2.0.8.0
Boost: | 1.74.0
OpenSSL: | 3.0.11
zlib: | 1.2.13

qBittorrent: 4.6.2
Operating system: AlmaLinux: Linux 5.14.0-362.8.1.el9_3.x86_64 #1 SMP PREEMPT_DYNAMIC Tue Nov 7 14:54:22 EST 2023 x86_64 x86_64 x86_64 GNU/Linux
Qt: 6.6.1
Libtorrent: 2.0.9.0
Boost: 1.82.0
OpenSSL: 3.1.4
zlib: 1.3

What is the problem?

There seems to be a setting or bug that doesn't allow me to reach speeds greater than 20 MB/s on both a RaspberryPi 4 (4 GB of RAM, 1 TB USB3 external hard disk, and Raspbian OS) and a Lenovo Core i7 (16 of RAM, 500 GB internal SATA SSD, and AlmaLinux OS). My laptop with Windows 11 reaches 130 MB/s on the same 2.5 Gbps network. On all these devices the torrent tested was the latest image of Kali Linux.

Steps to reproduce

1. Run a docker/podman container with the settings indicated here: https://hub.docker.com/r/linuxserver/qbittorrent
2. Open the web UI via browser and log in
3. Start downloading this torrent https://cdimage.kali.org/kali-2023.4/kali-linux-2023.4-installer-everything-amd64.iso.torrent

Afterwards, I tried disabling all limitations in Tools > Options > Connection > Connection Limits and removing the limits in Tools > Options > Speed, but the result was the same.

Additional context

No response

Log(s) & preferences file(s)

No response

[stalkerok]

Libtorrent: 2.0.9.0

try testing with libtorrent 1.2.x

[vickdini]

Thanks for replying. I tried this docker image linuxserver/qbittorrent:libtorrentv1-version-release-4.6.2_v1.2.19:

qBittorrent: 4.6.2
Qt: 6.6.1
Libtorrent: 1.2.19.0
Boost: 1.84.0
OpenSSL: 3.2.0
zlib: 1.3.0.zlib-ng

Initially, the speed reached 33 MB/s but after a few seconds it became 15 MB/s.

[vickdini]

On the Windows 11 PC I mentioned, I ran a container based on this image lscr.io/linuxserver/qbittorrent:latest:

Qt: 6.6.1
Libtorrent: 2.0.9.0
Boost: 1.82.0
OpenSSL: 3.1.4
zlib: 1.3

The maximum download speed reached was 25 MB/s.

[vickdini]

When I tried running a container based on this image on my Windows 11 PC, the speed was around 25 MB/s: linuxserver/qbittorrent:libtorrentv1-version-release-4.6.2_v1.2.19:

qBittorrent: 4.6.2
Qt: 6.6.1
Libtorrent: 1.2.19.0
Boost: 1.84.0
OpenSSL: 3.2.0
zlib: 1.3.0.zlib-ng

[Sophist-UK]

There are lots of reasons that network speeds can be limited.

What is the result of running a broadband speed test on the rPi? This should help decide whether this is a qbt-specific issue or a more general network issue with the rPi.