[rsynnott]

Huh, really? I had a 2014 or something rMBP in work at one point; was almost certain it had a USB2 SD card reader.

EDIT: According to Apple, all the laptops are USB2: https://support.apple.com/en-us/HT204384

Desktops are PCIe.

[sigjuice]

I have a 2015 MacBook Air and wanted the SD card reader to belong to a Linux guest inside VMWare Fusion (for dd'ing custom RPi images). I just couldn't get it to work. Then I found this article https://kb.vmware.com/s/article/1035825 which says This issue occurs because the SDXC card slot included in newer Mac models is connected to the Mac using the PCIe bus and not using the USB bus that the original SD card slot uses.