Since upgrading to the Mac Pro 2019, all my card readers where very slow, only getting 10-20% of the speed they should get.
It's a LEXAR 3.0 USB card reader, Lexar XQD card reader and a RED minimag card reader.
I replaced the cable for the RED (USB Type-C to Type-A 3.1), and now my speeds went up from 20MB/s to 300MB/s. Should I buy new cables for the Lexar readers (USB 3.1 cables) or is it a OSX problem or do I need a driver update?
Mac Pro
Problems can occur on the Mac if the first device seen since startup was a USB-2 device. In this case, the bus can get "stuck" at USB-2 speeds. It will stay this way until you do an SMC Reset, or power down and startup again later.
menu > about this Mac > (system report) > USB ...
Check carefully for whether your Mac thinks this Bus is a USB-2 Bus, If so, it may be "stuck".
Problems can occur on the Mac if the first device seen since startup was a USB-2 device. In this case, the bus can get "stuck" at USB-2 speeds. It will stay this way until you do an SMC Reset, or power down and startup again later.
menu > about this Mac > (system report) > USB ...
Check carefully for whether your Mac thinks this Bus is a USB-2 Bus, If so, it may be "stuck".
Hi Grant, these are USB 3 cables I am using, still slow speeds, all blue colored.
Thanks Grant, I'll give it a shot!
When you plug in with cable that is only USB-2, you limit your maximum transfer speeds to USB-2 speeds. These cables have only the four obvious conductors opposite the plastic alignment plug.
USB-3 cables add an additional Five conductors, and add speed by going double-rail (push-pull or balanced drivers and receivers) and in some cases double-rail (two pathways). They can run MUCH faster this way. The additional conductors are deeper inside the connectors on both sides, and a frequent (but not 100 percent) convention is that the plastic plugs are Blue in color. Apple does not color their plugs blue.
Slow USB speeds with card readers.
