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flow of data to or from the disks and controls the heads. The location of data on each disk is logically maintained in
concentric tracks divided into sectors. The host computer sends instructions to the controller to read data from or
write data to the disks, based on logical track and sector locations. Guided by instructions from the controller, the
HSA pivots in an arc across the disk until it reaches the selected track of a disk, where the data is recorded or
The storage capacity of a hard drive is determined by the number of disks and each disk's areal density (track
density multiplied by bit density), which is a measure of the amount of data that can be stored on the recording sur-
face of the disk per unit area. Head and magnetic media technologies are two of the key technology components of
hard drives affecting areal density. We develop and manufacture a substantial portion of the heads and magnetic
media used in our hard drive products. As areal density increases, achieving a given drive capacity potentially reduces
product costs over time through reduced component requirements. We also invest considerable resources in research
and development, manufacturing infrastructure and capital equipment of head and magnetic media components in
order to secure our competitive position and cost structure.
Solid-State Drives
Solid-state drives use semiconductor, non-volatile media, rather than magnetic media and magnetic heads, to
store and allow fast access to data without any moving parts. The cost per bit of solid-state drives is more expensive
than hard drives, but the higher input/output ("IO") performance makes solid-state drives an attractive new tier of
storage that fits between DRAM memory and hard drives. Solid-state drives are finding growing usage in enterprise
storage systems and servers in applications that demand the highest IO performance.
The non-volatile memory in use today for solid-state drives is NAND flash technology. While Single Level Cell
("SLC") Flash provides the highest endurance and performance, the optimal balance of price and performance is usu-
ally achieved through the use of Multi-Level Cell ("MLC") Flash. Multiple NAND Flash die are used on a single
PCBA and connected in parallel through a controller to the host bus. Various performance classes of solid-state drives
are created by varying the number of parallel NAND channels and the speed of controller logic and firmware. The
controller contains hardware logic and firmware to buffer the data flow to and from the host, to the NAND Flash, and
to manage the reliability and performance of the NAND Flash media.
The typical host interfaces for solid-state drives include PCIe, SAS and SATA. PCIe products typically offer the
highest performance and come on edge cards that plug into the PCIe bus. PCIe defines the hardware and electrical
interface but the software protocols are still proprietary today. New standards such as NVMe and SCSI express are
emerging to bring more standardized software protocols for communicating with PCIe solid-state drives. SAS and
SATA products utilize standardized interfaces similar to hard drives and come in 2.5-inch form factors with differing
package heights depending on the application and usage. The typical power consumption for the SAS and SATA
interfaces is similar to hard drives, while the power consumption of PCIe form factor devices is typically higher.
Solid-State Hybrid Drives
Solid-state hybrid drives combine semiconductor non-volatile memory, typically NAND Flash, and magnetic rotat-
ing storage in one device. The capacity of the non-volatile memory is typically 8 GB to 32 GB. The prevalent usage of
these hybrid drives is in notebook computers. The non-volatile memory and control electronics are mounted on the same
board as the HDD electronics and share the same host SATA interface as hard drives. The non-volatile memory is utilized
as a non-volatile cache to enhance input/output performance, to reduce latency on boot up of the system, and to reduce
power consumption (by allowing the hard drive to spin down more often). The key challenges of adding the non-volatile
memory to the hard drive card are in adding the control electronics for the NAND Flash, the firmware to manage the
NAND Flash, qualifying the NAND Flash memory for use in this application, and the algorithms and new software
commands sets to manage data between the non-volatile memory, the HDD, and the host system.
Our products generally leverage a common platform for various products within product families, and in some
cases across product families, resulting in the commonality of components which reduces our exposure to changes in
demand, facilitates inventory management and allows us to achieve lower costs through purchasing economies. This
platform strategy also enables our customers to leverage their qualification efforts onto successive product models. For
a discussion of risks related to technological innovations, see Item 1A of this Annual Report on Form 10-K.