You're mixing up bits (Mb/s) and bytes (MB/s). Some SD cards are rated at up to 300MB/s, about 10x what USB2 can deliver. It often used to be the case that int

You're mixing up bits (Mb/s) and bytes (MB/s). Some SD cards are rated at up to 300MB/s, about 10x what USB2 can deliver. It often used to be the case that internal SD card readers are USB2, even when the device has an USB3 port.