传输守护进程比传输-gtk慢得多

我正在transmission-daemonUbuntu 20.04 上进行实验。它工作正常，但速度非常慢。这是一个广泛可用的 torrent 示例（tmr是 的别名transmission-remote）：

$ tmr -a "https://releases.ubuntu.com/20.10/ubuntu-20.10-desktop-amd64.iso.torrent"
localhost:9091/transmission/rpc/ responded: "success"

即使 5 分钟后，下载速度仍然低于 20 kB/秒：

$ tmr -l
ID     Done       Have  ETA           Up    Down  Ratio  Status       Name
   1     0%    2.98 MB  1 days       0.0    19.0    0.0  Downloading  ubuntu-20.10-desktop-amd64.iso
Sum:           2.98 MB               0.0    19.0

但是，将相同的 torrent 文件提供给transmission-gtkget 几乎立即可以达到数百 kB/秒的下载速度：

下面是设置转储。下载速度限制已停用，这不是原因。还能是什么？

$ transmission-daemon --dump-settings
{
    "alt-speed-down": 50,
    "alt-speed-enabled": false,
    "alt-speed-time-begin": 540,
    "alt-speed-time-day": 127,
    "alt-speed-time-enabled": false,
    "alt-speed-time-end": 1020,
    "alt-speed-up": 50,
    "bind-address-ipv4": "0.0.0.0",
    "bind-address-ipv6": "::",
    "blocklist-enabled": false,
    "blocklist-url": "http://www.example.com/blocklist",
    "cache-size-mb": 4,
    "dht-enabled": true,
    "download-dir": "/home/user/Downloads",
    "download-queue-enabled": false,
    "download-queue-size": 30,
    "encryption": 1,
    "idle-seeding-limit": 30,
    "idle-seeding-limit-enabled": false,
    "incomplete-dir": "/home/user/Downloads",
    "incomplete-dir-enabled": false,
    "lpd-enabled": false,
    "message-level": 2,
    "peer-congestion-algorithm": "",
    "peer-id-ttl-hours": 6,
    "peer-limit-global": 200,
    "peer-limit-per-torrent": 50,
    "peer-port": 51413,
    "peer-port-random-high": 65535,
    "peer-port-random-low": 49152,
    "peer-port-random-on-start": false,
    "peer-socket-tos": "default",
    "pex-enabled": true,
    "port-forwarding-enabled": true,
    "preallocation": 1,
    "prefetch-enabled": true,
    "queue-stalled-enabled": true,
    "queue-stalled-minutes": 30,
    "ratio-limit": 2,
    "ratio-limit-enabled": false,
    "rename-partial-files": true,
    "rpc-authentication-required": false,
    "rpc-bind-address": "0.0.0.0",
    "rpc-enabled": true,
    "rpc-host-whitelist": "",
    "rpc-host-whitelist-enabled": true,
    "rpc-password": "{9b7fdcbb3b3e63523e990b9eb6300d9cad8572f9MbOKm.TX",
    "rpc-port": 9091,
    "rpc-url": "/transmission/",
    "rpc-username": "",
    "rpc-whitelist": "127.0.0.1",
    "rpc-whitelist-enabled": true,
    "scrape-paused-torrents-enabled": true,
    "script-torrent-done-enabled": false,
    "script-torrent-done-filename": "",
    "seed-queue-enabled": false,
    "seed-queue-size": 10,
    "speed-limit-down": 100,
    "speed-limit-down-enabled": false,
    "speed-limit-up": 100,
    "speed-limit-up-enabled": true,
    "start-added-torrents": true,
    "trash-original-torrent-files": false,
    "umask": 18,
    "upload-slots-per-torrent": 14,
    "utp-enabled": true
}