The latency for USB3 is ~30 μS.

I don't think it's a USB protocol problem but rather a driver/manufacturer problem.

If I recall correctly MIDI itself had a typical latency several milliseconds on classic-era dedicated hardware.

Usually the software using the interface (pro tools / ableton) has settings to tweak audio latency via buffer size for audio. I have not had issue with this or midi, and I record a fair amount. Motu makes a good cheap audio usb-c interface.

> USB can't offer as low latency as a piece of well-designed hardware plugged directly into your PCI bus, at least in my own limited experience.

This may be true but I've never had latency issues with USB soundcards. Right now I have a Line6 Helix Floor unit that I use to play guitar with. I can route the audio through the Helix effects, into Logic and back to Helix for more post-processing and have no latency problems.

I have had other brands and models and none introduced perceivable latency.

I don't use MIDI but I doubt it requires less latency than live guitar playing.

I had a PCIe soundcard a few years ago that made it almost impossible to get rid of ground hum though.

I also have latency issues with USB soundcards and MIDI devices, specifically. Tried multiple vendors and in each one introduced ~100-200 milliseconds of delay. The old PCI SoundBlaster Audigy card I had 20 years ago with a the standard DIN MIDI interface was orders of magnitude better, even running Windows XP.

For audio is that via Directsound (if that's still a thing), ASIO or what?

Last time I did audio, installing ASIO4ALL was essential.

MIDI latency is a pain in the ass, audio latency is negligible with any USB soundcard I've used, buffer sizes and latency compensation in DAWs matter. Adjusting your MIDI timing to compensate the jittery of MIDI on a PC is also important.

Or get an external MIDI clock like the E-RM Multiclock and never bother about MIDI latency issues. Audio is completely fine, 30-50μs of latency won't ever be perceptible to humans, the latency of MIDI will.

This is emphatically not true for USB interfaces in general.

In particular, the first readily available set of benchmark results I was able to find[1] suggest the difference in audio (not MIDI) latency between the lowest-latency PCIe cards and the listed USB devices (RME Fireface UFX+ USB3 and RME Babyface Pro [USB2]) is under a millisecond.

While I couldn't find similar results for MIDI I/O, it seems unlikely that either of these USB devices' MIDI interfaces would introduce an order of magnitude more latency than their audio counterparts.

[1] https://gearspace.com/board/showpost.php?p=15796206&postcoun...

USB _is_ a well-designed hardware plugged directly into your PCI bus.

I'm not convinced.

https://www.bleepingcomputer.com/news/security/heres-a-list-...

Wait until you see the how many attacks can be carried out using Internet Protocol.

I'm also not the one making the claim that its well designed either.

USB is purely pooled by the host, no Bus Mastering, no DMA. Bunch of frequent interrupts (125us uSOF) that need to be handled by the CPU. USB 2.0 is so heavy its mere presence in a computer (idle pooling something plugged in) visibly slows down any <1GHz computer (halving IDE transfers for example https://www.vogons.org/viewtopic.php?t=89651). Users didnt notice because 2.0 started showing up in 2002 together with >2GHz CPUs.