Setting Global Rate Limits Upload Speed also throttles download speeds.

qBittorrent & operating system versions

Tested with 4.5.5 and 4.6.4 x64 Windows 11 (10.0.22xxx)

What is the problem?

Settings > Options > Speed > Global Rate Limits > Upload:

Limiting Upload speeds also heavily throttles download speeds.

I tested a few Upload Rate limits:

• 1 KiB/s drops download speed by about 95%
• 5 KiB/s by about 80%
• 10 KiB/s by about 20%
• 20 KiB/s by about 10%
• 40 KiB/s and above to unlimited gets normal download speeds.

For reference, at uncapped Upload Rate my upload fluctuates around 20-80 KiB/s.

Additional context

This is particularly problematic and counter-intuitive because throttling upload is one of the first things to try when troubleshooting unusually low download speeds. Whether there was a systematic error or just by bad luck for some time, this step ensures that there is systematic error going forward.

For comparison, this is not a problem in utorrent. Upload speeds and slots could even be limited down to 0 wherever possible, and downloads continue at full speed.