qBittorrent official forums

Hello good day.

I do not know if it will be a problem or it is its natural functioning, but I mention it.

I have the qb installed on a Windows Server 2016, Windows is installed on a RAID1 SSD 2X250GB, I use the temporary folder (SSD 2x250GB SSD RAID0) to download the files there first, and then automatically pass them to their destination (8X10TB RAID5).

When it starts to download 1 file in the temporary folder, the active torrents (active 20 or 30) are collapsed, and the upload speed stops. The download starts consuming the entire bandwidth, but from the middle of the file, the speed is reduced to almost half the bandwidth.

Once you have downloaded the file to the temporary folder, it takes approximately 30 seconds (sometimes it is instantaneous) to start the transfer from the temporary folder to your destination.

Do any of you know what this behavior is due to?

Thank you.

Possibly bufferbloat (when high DL speeds cause UL speeds to drop) and/or disk I/O overload (when copying from SSDs to to HDDs.)

Well yes, it can be an excess load. I'll be checking to see how it evolves with load and no load. Thank you!

Well I've been observing the behavior on the downloads in the temporary folder, and continues to do the same. When the files are downloaded to the temporary folder, the other files they are sharing (now there are 10 torrents sharing) pass at very very low speeds, once the file is downloaded to the temporary folder, everything returns to normal.

I put a graphic example.

The first photo is when there is nothing downloading, and everything works correctly.

The second photo is when there is a file downloading, and it is seen that the other files that are going up, the speed drops.

And the last photo, represents the graph of the time, where the peaks interpret that there is nothing downloading and the rise is normal, and in the process of the valley, it is when there is a file downloading.

"When it starts to download 1 file in the temporary folder, the active torrents (active 20 or 30) are collapsed, and the upload speed stops. The download starts consuming the entire bandwidth, but from the middle of the file, the speed is reduced to almost half the bandwidth."

Sounds exactly like no speed limits were set in qBitTorrent, or at least not speed limits that match your connection.

So what does your connection's speedtest graph (both down and up) look like?
Because if there's similar peaks-and-valleys in it as your 3rd pic in your last post, then there's something seriously wrong with your connection!

The connection works very well, because when I do not use the temporary folder, everything works correctly.

Run a test with a ramdrive -- keep the torrent on the ramdrive rather than having the contents moved to a HDD when done.

There shouldn't be any slowdowns due to using a ramdrive, but there might be slowdowns like you've seen so far if qBT has bad multi-torrent handling.

[quote="Switeck"]
Run a test with a ramdrive -- keep the torrent on the ramdrive rather than having the contents moved to a HDD when done.

There shouldn't be any slowdowns due to using a ramdrive, but there might be slowdowns like you've seen so far if qBT has bad multi-torrent handling.
[/quote]

I do not like the program to create RAMDrives, the problem is not when Qbt transfers the file to the final destination, but when you are downloading the file in the temporary folder. Once the file is no longer downloaded and transferred to the destination, everything returns to normal.

Try on a separate HDD/SSD then. If the slowdown still persists, either qBT's settings are to blame (possibly because they don't match up well with your connection's capabilities) AND/or qBT has serious bugs in I/O or bandwidth usage.

[quote="Switeck"]
Try on a separate HDD/SSD then. If the slowdown still persists, either qBT's settings are to blame (possibly because they don't match up well with your connection's capabilities) AND/or qBT has serious bugs in I/O or bandwidth usage.
[/quote]

Right now I can not try another disk. The current configuration of the temporary folder, is a Samsung 250GB SATAIII RAID0 SSD connected directly to the motherboard, and the disks work correctly.

What I can leave you is the current configuration that I have in the Qbt. I leave some screenshots, it's in Spanish (I'm from Valencia, Spain) but I'm sure you'll understand it perfectly. I only use private trackers.

Here I was hoping for something obviously wrong...and I don't see anything like that in your settings.
I'm not sure what qBT's default values are for max upload slots (global and per torrent) if no limit is set for them. That doesn't seem a likely cause of your problems, but it's at least a remote possibility.

Another sad possibility is the CPU may be overloaded when downloading at 70+ MB/sec and that may cause other torrents upload speeds to fall immensely. You can check CPU usage in Windows Task Manager -- qBitTorrent may be maxing out a cpu core (or virtual core, if hyperthreading is active).
Increasing the number of threads qBT can use from 4 to 8 (it's above the 98 MB cache size in advanced settings) might help if your CPU is at least a 4-core, especially if it has hyperthreading as well.

[quote="Switeck"]
Here I was hoping for something obviously wrong...and I don't see anything like that in your settings.
I'm not sure what qBT's default values are for max upload slots (global and per torrent) if no limit is set for them. That doesn't seem a likely cause of your problems, but it's at least a remote possibility.

Another sad possibility is the CPU may be overloaded when downloading at 70+ MB/sec and that may cause other torrents upload speeds to fall immensely. You can check CPU usage in Windows Task Manager -- qBitTorrent may be maxing out a cpu core (or virtual core, if hyperthreading is active).
Increasing the number of threads qBT can use from 4 to 8 (it's above the 98 MB cache size in advanced settings) might help if your CPU is at least a 4-core, especially if it has hyperthreading as well. Could it incorporate 20 threads into the configuration it refers to?
[/quote]

The processor is also no problem for the load it can support, since it is a Xeon E5-2630L V4 10 cores 20 threads. I do not know if you recommend any configuration to work better qbt.

Yes, you could raise the number of threads qBT uses to 16 or 20 and it might be faster/smoother.
Might want to also set the cache size to either -1 (auto-configure) or 500-1000 MB, since your speeds are so high.

The cache configuration is already automatic. I will incorporate 20 asynchronous threads and I will continue checking the operation of qbt. Thanks for the help.