Network slows down after installing qBittorrent 4.6.0 (lt20 qt6)

[Apegapen]

qBittorrent & operating system versions

qBittorrent 4.6.0 (lt20 qt6)
Windows 10-64 (10.0.1xxxx)

What is the problem?

Since installing qBittorrent 4.6.0 (lt20 qt6) I have many problems with my network: My webbrowser (Firefox 96.0.3/64) fails to contact websites. After the contact is made at last, everything seems OK.
Went back to qBittorrent 4.5.5 and problems are gone.....

Steps to reproduce

Fenomenon was always there since installing qBittorrent 4.6.0 (lt20 qt6)

Additional context

No response

Log(s) & preferences file(s)

No response

[luzpaz]

Paste Full version info of what you are using please (both 4.6.0 and 4.5.5)

[Apegapen]

qbittorrent_4.5.5_lt20_qt5_x64_setup

Uninstalled:
qbittorrent_4.6.0_lt20_qt6_x64_setup

[Apegapen]

I am using Firefox 96.0.3 because that is the last version where you can properly choose in which directory you want to save a download.
My Windows 10 is updated to the latest version.

[Pentaphon]

(lt20 qt6)

Stop using that version and just use the 1.2.x libtorrent version. v2 has issues that cause slowdowns.

#16043

[Apegapen]

OK, but that was not the problem....

[Pentaphon]

OK, but that was not the problem....

Install 4.6.0 with 1.2.x and see what happens. Try it. Don't use the one with libtorrent v2.

[glassez]

OK, but that was not the problem....

Don't use the one with libtorrent v2.

Let everyone decide for themselves what version to use. libtorrent 2.0 is not an "absolute" bad choice, it all depends on the specific use case.

[Pentaphon]

Let everyone decide for themselves what version to use. libtorrent 2.0 is not an "absolute" bad choice, it all depends on the specific use case.

I understand what you're saying but whenever people complain about their libtorrent v2 install (which isn't the default anyway) being slow, going to v1 always seems to fix their issue. I'm willing to bet that this issue is actually a duplicate of the same issue being posted over and over again due to the issues with libtorrent v2, which needs to be fixed by testers, not users.

[Biceeeeepss]

Let everyone decide for themselves what version to use. libtorrent 2.0 is not an "absolute" bad choice, it all depends on the specific use case.

I understand what you're saying but whenever people complain about their libtorrent v2 install (which isn't the default anyway) being slow, going to v1 always seems to fix their issue. I'm willing to bet that this issue is actually a duplicate of the same issue being posted over and over again due to the issues with libtorrent v2, which needs to be fixed by testers, not users.

After running some tests by myself on my laptop that has an NVMe SSD drive libtorrent v2 is better than v1 (something due to cache probably), libtorrent v1 was causing for qbittorent to use more RAM than it should with the same torrents, right now it stays at 19 MB RAM and it will not go further than 50 MB.

Anyway, I had some problems also with qbittorrent in the last week or so that would slow down internet and I found that only a router option was to blame, what is strange is that before I didn't had this problem, so probably TP Link can update firewall rules on their routers.
I'm using Tp Link AX53, I disabled "SPI Firewall" and everything is fine, otherwise I don't get full speed on Wireless and also torrents programs affects my internet on all devices.
Maybe this will help someone else too.

[Pentaphon]

Even if you guessed right, then that's more like a temporary workaround than a proper explanation or a fix.

That's another issue entirely because users are supposed to be using the default 1.2.x version and not the lt20. This issue is one of many duplicate threads just complaining about lt20. It's a workaround, but telling people to use lt20 if they want is just creating too many needless duplicate issues.

The lt20 needs extensive testing by dedicated beta testers before it can be rolled out to users. I'm betting that the 2.1.x series will finally get it to a usable state.