Potentially helpful qBittorrent settings/tips

[Hypertext1071 6]

Hi all,

I've always been trying to maximize my seeding speeds when using qBittorrent, and a lot of information I found online was not very helpful. My setup is qBittorrent 4.3.9 from hotio with Gluetun on TrueNAS Fangtooth. My best speeds have been obtained on the servers Taiyangshou and Vindemiatrix with WireGuard. I am in North America, but I don't think latency matters as much as I originally thought for P2P use cases. These two servers in the Netherlands have been very nice and I definitely recommend trying out different servers.

In my use case, I have hundreds of larger torrents, maybe half are 50 GB+. I have found that since I am using hard drives, the random reads will quickly overwhelm them even with ARC and L2ARC, thus setting the "Global maximum number of upload slots" is very useful (this is the only one I have turned on in the "Connection" tab). This limits the total number of peers you can upload to globally, and the idea is that you limit the total amount of random reads this way. The magic number that works the best for me is 50, and I recommend trying around this range by increments of 5 might work nice. Additionally, I could keep increasing the "Global maximum number of upload slots" without much rise in iowait, but total throughput would decrease. Therefore, when optimizing this setting it is a balance between enough slots to saturate your bandwidth, but not too much where it spreads the bandwidth too thin and negatively impacts total throughput. I have also attached the advanced settings that I changed which seemed to make the greatest impact.

Send buffer watermark: 6144 KiB
Send buffer low watermark: 3072 KiB
Send buffer watermark factor: 200 %
Socket backlog size: 4096

I hope this is helpful!

Best,
Hypertext1071


Edit: For further tuning this might be helpful: https://github.com/felikcat/seedbox-tutorial.