Seagate ST9500420AS Momentus 7200.4 SATA Product Manual - Page 11

2.2 Formatted capacity Model ST9500420AS and ST9500420ASG ST9320423AS and ST9320423ASG ST9250410AS and ST9250410ASG ST9160412AS and ST9160412ASG ST9120410AS and ST9120410ASG Formatted capacity* 500 Gbytes 320 Gbytes 250 Gbytes 160 Gbytes 120 Gbytes Guaranteed sectors 976,773,168 625,142,448 488,397,168 312,581,808 234,441,648 Bytes per sector 512 512 512 512 512 *One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment and formatting. 2.2.1 LBA mode When addressing these drives in LBA mode, all blocks (sectors) are consecutively numbered from 0 to n-1, where n is the number of guaranteed sectors as defined above. See Section 4.3.1, "Identify Device command" (words 60-61 and 100-103) for additional information about 48bit addressing support of drives with capacities over 137 Gbytes. 2.3 Default logical geometry Cylinders 16,383 Read/write heads 16 Sectors per track 63 LBA mode When addressing these drives in LBA mode, all blocks (sectors) are consecutively numbered from 0 to n-1, where n is the number of guaranteed sectors as defined above. 2.4 Physical organization Drive model ST9500420AS and ST9500420ASG ST9320423AS and ST9320423ASG ST9250410AS and ST9250410ASG ST9160412AS and ST9160412ASG ST9120410AS and ST9120410ASG Read/write heads 4 3/4 2 2 1/2 Number of discs 2 2 1 1 1 Momentus 7200.4 SATA Product Manual, Rev. A 5