> There is no technical reason for UDP to be slower than TCP (at CPU level).
The technical reason is 30+ years of history of TCP being ≥90% of Internet traffic and services. There's several orders of magnitude in resources more spent to make TCP fast starting at individual symbols on Ethernet links all the way up into applications.
If you're so sure of this, why did you even ask to begin with?
(Also, what is your definition of "quick"? I have no association for that particular wording, are you referring to achievable thruput, CPU load, latency, congestion control, …?)
Are you a troll? The question was about H1 quicker than H3, and the OP explains the difference by saying it was TCP quicker than UDP, which is not a reasonable explanation, so I asked for source.
But it was all about encryption (and only encryption) and how it was handled within the kernel, and I understood re-reading the first comment (before event sending mine).
Here "quicker" was about CPU load and well defined.
The technical reason is 30+ years of history of TCP being ≥90% of Internet traffic and services. There's several orders of magnitude in resources more spent to make TCP fast starting at individual symbols on Ethernet links all the way up into applications.