STORAGESecondary Storage

COMPUTER STORAGE Computers have two kinds of storage:

Primary StorageSecondary Storage

Primary storage is also called memory. Secondary storage is often called

storage. Individuals often do not distinguish

between these two types of computer storage.

SECONDARY STORAGE Unlike memory storage is NOT volatile,

so its contents last even when the power is turned off.

STORAGE TECHNOLOGY Magnetic

Hard drives, floppy drives Optical

CD/DVD drives/burners Integrated Circuit (IC)

Flash memory (USB sticks)Flash memory (SD,CF, etc [camera

memory]SSD (solid state drive) modern hard drives

for some notebook computers which can also be used in desktop computers.

MAGNETIC STORAGE Hard (Fixed) disk is the most common

kind. Virtually every computer has a hard disk. External hard disks are also available.

Platters/Surfaces Tracks Sectors Disk blocks/clusters Approximate Costs:

Internal 1000GB = $80 ( 8cents / gb)External 1000GB = $90 (USB only)

OPTICAL STORAGE One spiraling track from center to outside. Compatible with standard CDs and DVDs. Currently CD only drives are scarce but DVD

drives are compatible with CD drives. Blu-ray drives are downward compatible but

are not as popular because of DRM concerns. Approximate Costs:

Internal Drive ~ $20/ Internal burner ~ $25External Drive ~$35 /External burner ~ $40-50 Internal Blu Drive ~$60-75 / Burner ~ $100External Blu: $100 / Burner ~ $150 or so

IC STORAGE No moving parts Therefore speed is faster than either

optical or magnetic Breaks down after lots of use (normally

measured in the 100s of thousands of times.

Approximate Costs:USB stick:SD card: $1-2 per gb for medium sizes

8gb=12, 32gb= 50, 64gb= 150 128gb=1100

SSD drive: about $2/gb