I have run into some disappointing performance for CDC/ACM devices using OS default drivers (OUT performance significantly poorer than IN performance, for instance.) Before I go around trying to optimize the device code, I thought I'd do a bit of research, and I found here:
Reports are that the Windows [CDC/ACM] driver is slow (640Kbit/sec)
However, that appears to be a very old comment. Is it still true of current Windows (W10, W11)? What about other OS CDC/ACM drivers? (I seem to have similar performance issues on MacOS 10.13, for instance.)
(Testing with TinyUSB on RPi Pico and SAMD cpus, BTW.)