Apple article http://support.apple.com/kb/ht3553#4 is not specific as to what speed, and Apple tech support discredited the article, so reign of confusion. Article Q&A says: "What is the maximum speed that my computer can use when reading and writing to an SD card in the SD card slot? Macs that use the USB bus to communicate with the SD card slot have a maximum speed of up to 480 Mbit/s. Newer Macs use the PCIe bus to communicate with the SD card slot and can transfer data at a much faster rate." Presumably, the mid-2011 iMac would be the "newer" mac, but when I asked Apple tech support to tell me the data rate he said it was wrong to infer the mid-2011 had the SD slot on a PCIe, but rather, it has it on a USB bus. I suppose Apple tech support is right and the article is wrong or referring to a future imac. Anyone have any additional info on this?