5. Tech Tips
page 27
LaCie d2 Hard Drive Serial ATA
User’s Manual
5.2. Available Storage Capacity
A gigabyte (GB) means 1,000,000,000 bytes. In order to utilize a hard disk drive, it has to be formatted first. Formatting a
disk consists of the following: the operating system erases all of the bookkeeping information on the disk, tests the disk to
make sure that all of the sectors are reliable, marks bad sectors (i.e., those that are scratched) and creates internal address
tables that it later uses to locate information. Once formatted, the actual available storage capacity varies, depending on
operating environment, and is generally about 5 to 10% less than the non-formatted capacity.
5.3. Optimizing Data Transfers
Data transfers are the flow of data that accomplishes a task, usually related to moving data from storage to computer RAM,
or between storage devices. With external drives, such as the LaCie Hard Drive, the data is transferred from the drive to the
computer via the Serial ATA interface. The data is fed from the drive through the Serial ATA port on the drive, and passes to
the computer through the Serial ATA host-bus adapter interface.
Tech Note:
For more information on the Serial ATA interface, please see:
6. Serial ATA Questions & Answers
.
At the time of publication (July, 2004), computer manufacturers have not begun to implement external Serial ATA connectors,
therefore the use of a third-party PCI host-bus adapter card is necessary to allow for Serial ATA connectivity.
The Serial ATA interfaces specify certain requirements, filed under the OHCI (Open Host Controller Interface) standards. All
LaCie drives comply to OHCI standards and have been rigorously tested on computers that have host bus adapters that also
comply to OHCI standards. Unfortunately, not all manufacturers respect these guidelines, and anomalies may arise with
computers that have host bus adapters that do not conform to OHCI standards.
For the best performance, during data transfers, it’s best to wait before launching other applications that will be using the
same port. Another important factor in file transfer speeds is how the drive has been formatted. For more information in
choosing the correct file system format, please see section
5.1. File System Formats
.
If you do not have a native Serial ATA port, LaCie offers Serial ATA host bust adapter cards, also known as PCI or
PC/PCMCIA cards, that have been tested and comply with LaCie drives. Please contact your reseller or LaCie Customer
Support for more information.
