Torrents - Should we still avoid μTP?

[yoyall 6]

Hi Everyone!

Over the years there's been advice to avoid μTP in torrent clients like qBittorrent and use TCP exclusively (when using a VPN). And I have followed this advice.

But now I wanted to check in again to see if that is still the case - Is it still recommended to avoid μTP?

I'm asking for two reasons - 1) when this advice first came out I think we only really had OpenVPN. Now the default is Wireguard. Does that change anything?

And also 2) I recently had a couple of torrents I was trying to download and they were stalled and dead. But when I enabled μTP with TCP, they sprang to life and downloaded lickety-split.

So, just wanted to see if anything had changed - or whether my experience was just an anecdotal one-off.

Cheers!

[OpenSourcerer 1487]

10 hours ago, yoyall said:

But now I wanted to check in again to see if that is still the case - Is it still recommended to avoid μTP?

uTP never changed.  Though, there are some tests here and there that say mixed mode (TCP + uTP) can be faster, one just needs to wait a few minutes for uTP to ramp up. I generally still recommend TCP only, though, the difference is marginal.
 

10 hours ago, yoyall said:

I'm asking for two reasons - 1) when this advice first came out I think we only really had OpenVPN. Now the default is Wireguard. Does that change anything?

Still UDP, so uTP will behave similarly.
 

10 hours ago, yoyall said:

And also 2) I recently had a couple of torrents I was trying to download and they were stalled and dead. But when I enabled μTP with TCP, they sprang to life and downloaded lickety-split.

Then maybe in your case mixed mode is indeed better. It's not like having this enabled will somehow cause your OS to uninstall. Or manipulate the weather around you and spawn an EF5 tornado on the spot.  As written, I usually recommend TCP only because in most cases it just avoids headaches.

[yoyall 6]

@OpenSourcerer Very helpful, informative - and entertaining 🤣 - response as always. Think I'll just stick with TCP. Thanks so much for the update! 🙏

[go558a83nk 378]

on my seedbox I just tested mixed mode vs TCP only with the libtorrent mixed mode algorithm set to peer proportional.  mixed mode was super slow.  I switched to TCP only and restarted the torrent client and speeds were nearly 10 times faster.   maybe switching the mixed mode algorithm to prefer TCP will be better.  I'll have to test that next time.

[yoyall 6]

Been doing some informal, ad-hoc testing and it seems that TCP is *usually* faster...but every once in a while I still have a torrent that is only available via mixed μTP/TCP or is way faster with mixed μTP/TCP.

My strategy is going to use TCP as the default and then try mixed μTP/TCP if I'm having problems.  🧐

[OpenSourcerer 1487]

On 7/8/2025 at 2:46 PM, yoyall said:

My strategy is going to use TCP as the default and then try mixed μTP/TCP if I'm having problems.  🧐

You'll never have problems with TCP only, though, hence the recommendation.  It's like a high risk, high reward thing: By setting mixed mode, you may or may not see better throughput.
You may also induce constipation on the line, one that no laxative will ever cure.

[yoyall 6]

9 hours ago, OpenSourcerer said:

You may also induce constipation on the line, one that no laxative will ever cure. 

Words to live by! 🤣👍👍