Normal mode is the standard BIOS translation scheme. This mode does not support drives greater than 504 MB. Large mode is a generic translation scheme used by some BIOS’s to access drives up to 1 GB. Logical Block Addressing (LBA) mode is a more advanced method of translation than Large mode. LBA mode is a somewhat faster and can see drives 8.4 GB and greater.
What are the Cylinder, Head and Sector values [C/H/S] for ATA disk drive and how to find them?
C/H/S is an older method of identifying drive capacity and tracking the location of data on the drive. The C/H/S method was replaced with the Logical Block Addressing (LBA) when drives transitioned above 8.4 GBytes. If you are attempting to use a drive smaller than 8.4 GBytes then the C/H/S information can be found by searching the Product Finder in the bottom left corner of the Seagate support site.
For drives larger than 8.4GB it is recommended that the BIOS be allowed to automatically negotiate with the drive using the LBA method.
Note: Changing the C/H/S setting in the BIOS can make existing data on a drive unreadable.
Logical Block Addressing (LBA) is a mathematical scheme for addressing sectors, beginning at cylinder 0, head 0 and sector 1, which is equal to LBA 1. This scheme linearly maps the drive until the final physical sector is reached. LBA is efficient because it reduces some system overhead by not having to convert the operating system’s LBA to the BIOS CHS and then back to drive LBA.
