I have a Lexar CFexpress Type B card reader connected to my M1 Max MacBook Pro via USB-C. I am getting USB 2.0 speeds on the read/write; around 35MB/s. Any ideas what could be causing this?
It's definitely not the card; it's rated for 1700MB/s.
MacBook Pro (2020 and later)
Make sure you are using a Thunderbolt 3/USB3 Cable which has a lightning bolt icon on the connector. Do not use the Apple USB-C charging cable as it is only rated for the USB2 protocol & speeds when used as a data cable.
Make sure you are using a Thunderbolt 3/USB3 Cable which has a lightning bolt icon on the connector. Do not use the Apple USB-C charging cable as it is only rated for the USB2 protocol & speeds when used as a data cable.
What is the reader's and cable's rated speed? Rated speeds are always optimistic and represent. the very best you'll ever get under ideal laboratory conditions.
They're both USB 3.1, so it's advertised as 10Gb/s. I'm not expecting that, but it should be faster than 35MB/s, which is USB 2.0 speed. I'm guessing it's a problem with the device rather than the Mac now that I've done a little more research.
I appreciate the reply. I'll give it a shot with another cable; this was purchased from Amazon and is supposed to be USB 3.1, but it's entirely possible it's not labeled correctly.
USB-C device reading/writing at USB 2.0 speed
