What is "Ultra ATA CRC Error Rate"?
The UDMA controller performs error checking on the data it receives from the HDD, ensuring that the data was not damaged while being transmitted over the cable. Each time an error is detected, the controller requests a retransmission, thus slowing down the overall transfer speed. Lower values of "Ultra ATA CRC Error Rate" correspond to a higher number of errors, usually indicating a cabling problem.
Good old Google..
http://www.z-a-recovery.com/smart_faq.htm <--- Her fant jeg info.