Maybe? Been awhile since I’ve messed with my setup and while I don’t like slow, I prioritize security over speed so my settings might not be what you want anyway. so I’d recommend just looking up a guide; it is an extremely popular torrent client and there should be tons of guides out there. Or if you not sure which guide to use, just create a new post here - lot of people use it and probably have set it up from scratch more recently than me. I know some people say to open ports on the router but i’ve never liked the idea (I view it as less secure) but some people swear by it.
I can recommend that you test the following:
make sure you are using a VPN server that isn’t too far away. If you were in say San Franciso and selecting a VPN in New York or Europe, your speeds will be less than if you selected one in Seattle or Los Angeles
do a speed test off your vpn vs on it (e.g. speedtest.net). ALL VPNs will be slower than regular non-VPN due to the encryption and having less hops. But you can see how much difference it makes when you switch servers and if you have more than one VPN service, then you can find servers in the same city for both and compare which service is faster.
If your VPN has a modified WireGuard service (PIA and Nord both do IIRC), then that should be faster. I say modified bc the unaltered Wireguard spec has a privacy red flags so if you have a VPN service that offers it, make sure you read up or at least skim some reviews and whatnot to make sure they handled those issues that in a way that doesn’t leave your identity exposed. PIA and Nord both did that (I think Nord’s was called something else not actually WG but idr).
make sure you do your testing on popular torrents - but if it is anything you could get in trouble for, then you should do all the leak tests I mentioned above FIRST. Only mentioning, bc I had a friend that was testing his shit on some obscure thing he was looking for and saying it was slow but when i helped him configure his settings, we tested with something popular (i think whatever the current hottest show was) and he was actually getting a lot better speeds than he thought.
edit: just searched on dbzer0 and wasn’t seeing much on this. I did find a reddit post and a makeuseof guide that both mention stuff about improving speed. For the reddit one, I think the patched exe they are talking about is likely a dev build and since that was from a few years ago, whatever fix is probably already merged in and no longer needed. will compare the other settings vs mine and post back
edit2: are are the differences i have from the guide:
makeuseof has (Tools > Options > Speed) “Upload and download rate limits are set to infinity by default, and it’s recommended not to tinker with these limits. Most often, users limit the upload rate to save bandwidth and get faster download rates, but the torrent client’s choking mechanism compromises download rates when upload rates are limited, making the download process much slower.” - on mine, i had infinite down and was restricting upload. But I kind of think MUO’s advice is better and increased my upload amount. Mine was 100 KiB/s, now 1000 KiB/s. Only reason I don’t put it on infinite is I am on a capped internet and tend to leave my downloaded stuff around for sharing so I want to avoid uploads consuming too much of my monthly bandwidth and I don’t leave my client running 24/7 so not sure how reliable bandwidth settings are.
makeuseof has (Tools > Options > BitTorrent) "In the dropdown menu next to Encryption mode, select Allow Encryption. " but on mine I have it as “required Encryption” - probably this would make mine slower than the suggestion tho
Tools > Options > Connection settings I have “TCP and uTP” (same as MUO) but that old reddit thread was recommending only TCP.
MUO has (Tools > Options > Connections) : "Ensure the box beside Use UPnP / NAT-PMP port forwarding from my router is checked. " - as I mentioned, I don’t do port forwarding so I leave mine unchecked but there is probably a speed hit for this.
There was also something about "Don’t download multiple torrent files at the same time. This will then allocate all available bandwidth to downloading a single file, resulting in a faster download. " - I generally ignore this but there IS some truth to it. I have had hundreds of things queued before and gotten awful speeds. I recommend just not going overboard with how many you are running at once.
Tools > Options > Advanced: Find the network interface and select the one that corresponds with your VPN. If you aren’t sure, for most Windows users you can connect to VPN then find from command line using ipconfig /all and look for something that is NOT disconnected and probably has TAP-Windows Adapter Vx if using OpenVPN-Protocol (most VPNs) but might be different for wireguard. For Linux users, to show network interfaces run ip -4 -o -br addr - usually in linux ethernet interfaces start with an E and wifi interfaces start with a W, lo is localhost, and 99% of the time the vpn interface will be named tun0 if you are using a VPN with OpenVPN-protocol (most of them) but might be something different for wireguard or if you have customized things.