naKnow Lib

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# HDD

## System definition

  * HDD = Hard Disk Drive
  * Storage device that uses magnetic storage to save, store and retrieve data

### What is it used for?

  * Save, store and retrieve data
  * It is permanent storage, unlike volatile memory like RAM.
  * Can be used in desktops, laptops, servers or for external storage.


### Are they different types and technologies?

Interface:
  * SATA = Serial ATA
  * PATA = Parallel ATA
  * SCSI = Small Computer System Interface

Form factor:
  * 2.5 inch
  * 3.4 inch


## Life cycle

### Manufacturing

#### What is it made of?

An HDD is composed of the following elements:

Platters:
  * One or more
  * Double-sided
  * Glass substrates, coated with magnetic material
  * They are spinning, thanks to the motor.

Motor:
  * Spindle with motor

Read-write heads:
  * Positioned by actuators
  * It is flying 3 nm above the disk surface

Supporting electronics

#### How is it manufactured?

TBC

#### Who are the main manufacturers?

3 main manufacturers:
  * Seagate
  * Western Digital
  * Toshiba

#### Where are they located?

TBC


## Environmental footprint

### What are the main environmental impacts associated to the materials?

Materials used:
  * Aluminium, copper, steel
  * "rare earth" (for magnet)

### What are the main environmental impacts associated to the manufacturing processes?

TBC

### What are the potential parameters affecting environmental impact?

TBC

##  Next steps

### What do we know we don't know?

TBC

### What are the identified challenges?

TBC

### What paths/ideas should be explored?

TBC