USB CDC ACM max transfer speedhttps://devzone.nordicsemi.com/f/nordic-q-a/83705/usb-cdc-acm-max-transfer-speedHello ! I&#39;m using USB CDC ACM serial port in interrupt driven mode. I can see driver operate by 64 bytes chunks. Linux PC is used as data source and I can see 450KB/s in case of RX and about 250KB/S in case of TX. Does those digits are good enoughen-USTelligent Community 13Mon, 17 Jan 2022 13:37:51 GMTRE: USB CDC ACM max transfer speedhttps://devzone.nordicsemi.com/thread/348054?ContentTypeID=1Mon, 17 Jan 2022 13:37:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f378b245-e17a-4b5f-97a0-b43160ef5d6dHiihtaja<p>Thank you !</p> <p>Eugene</p><div style="clear:both;"></div>RE: USB CDC ACM max transfer speedhttps://devzone.nordicsemi.com/thread/348043?ContentTypeID=1Mon, 17 Jan 2022 13:00:34 GMT137ad170-7792-4731-bb38-c0d22fbe4515:c6bb4674-7928-4396-b2f2-59b718fa2055Sigurd<p><span>Hi,</span></p> <p><span> Those numbers seem to be in line with what we have found. In our testing we have found the CDC example to yield approximately 215kB/s transfer speed on Windows, and over 300kB/s on Linux.&nbsp;</span></p> [quote user=""]Or this is some fundamental constant&nbsp;<span>#define</span><span> </span><span>NRFX_USBD_EPSIZE</span><span> </span><span>64 e.g max packet size&nbsp; for full speed USB and basically everything&nbsp;already fast enough ?</span>[/quote] <p>Correct, 64 is the max for USB Full speed device.</p><div style="clear:both;"></div>