Just a short follow-up: The card (Samsung SD Pro 16GB) the internal O2 card reader writes to sequentially at 4.2mb/s handles 14.4 mb/s in the raspberry pi (and about 30mb/s in the O2 + windows 7): Raspberry: > ce@raspberrypi:~# dd if=/dev/zero of=/dev/mmcblk0 conv=fsync bs=4M count=256 > 1073741824 bytes (1.1 GB) copied, 74.4169 s, 14.4 MB/s SandyBridge Core i7 + O2 pci card reader (Linux 3.15.4): > dd if=/dev/sda of=/dev/mmcblk0 conv=fsync bs=4M count=256 > 1073741824 bytes (1.1 GB) copied, 258.515 s, 4.2 MB/s Any idea what I could do to find out why the internal card reader is so slow under Linux? Thank you in advance, Clemens -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html