m+storeMemory storage

Unit 02 – Computer Systems

BTEC Level 3 90-Credit Diploma for IT UsersLecturer: Owen Funnell

Memory and Storage

This Lesson….Recap of motherboardsRecap Processors

BTEC Level 3 90-Credit Diploma for IT UsersLecturer: Owen Funnell

End of the Lesson…Be able to explain the difference between memory and storage

Identify storage devices

Identify memory devices

System Memory (Page 28)

Lecturer: Owen Funnell

Memory is technically any form of electronic Storage.

If your computer's CPU had to constantly access the Hard Drive to retrieve every piece of data it needs, it would operate Very Slowly

When the information is kept in Memory, the CPU can access it much more quickly.

Most forms of memory are intended to store data temporarily.

When the power is removed it loses what is stored in it. This is called volatile memory

CPU

Memory

Storage



Random Access Memory

Read-only Memory

Cache

Flash Memory

Video Memory

Virtual Memory



CPU

Cache

RAM

Virtual Memory

Disk Storage

If your computer lacks the random access memory (RAM) needed to run a program or operation, Windows uses virtual memory to compensate.

Virtual memory combines your computer’s RAM with temporary space on your hard disk. When RAM runs low, virtual memory moves data from RAM to a space called a paging file. Moving data to and from the paging file frees up RAM to complete its work.



DDR is the standard for memory

Dual-Channel and Triple-Channel



Buying Memory PC 1 Gigabyte 970A-DS3P (Socket AM3) ATX Motherboard

PC 2 H81M-K microATX Motherboard

PC 3"Primo Nano 5X" D54250WYKH Intel Core i5 Haswell Micro PC

PC 4MSI GT70 2PC-1864UK Dominator

DDR3 2000(O.C.)/1866/1600/1333/1066 MHz memory modules

DDR3 1600/1333/1066 MHz

DDR3 1600MHz Dual Channel Kit

DDR 3 1600 Mhz

System Storage - Hard Drives (Page33)


There a two types of Hard DrivesHDD Hard Disk DriveSDD Solid State Drive

non volatile

DiskSpindle Head

Actuator Arm

Hard Drive Geometry

1. Cylinders Heads Sectors

CHS = Cylinders / Heads / Sectors

CHS = A method of giving addresses to data on a hard drive.

2. Cylinders

Each platter is divided into tracks.

All tracks on the same diameter, through all the platters are called a cylinder.

So a hard drive with 4 platters will have 8 tracks in the cylinder.

Hard Drive Geometry (Continued)

3. Heads

Every hard drive consists of platters and read-write heads.

The head value is the number of read-write heads in the drive.

If a drive has four platters, it usually has eight read-write heads, one on the top and bottom of each platter.

4. Sectors

A sector is like a slice of cake.

The sector value is the number of sectors in each cylinder, each sector consisting of 512 bytes.

BTEC Level 3 IT

5. Clusters

Clusters are a set of sectors, Typically 2 to 16 sectors in a cluster or allocation unit.

System Storage – Hard Drives (Page34)




What problems could a mechanical hard drive have?• Bad Sectors - A area of the hard disk drive that cannot hold data reliably because of

damage or error. Caused by bumping or banging the disk

• Lost Cluster - A lost cluster is a cluster that the operating system has classed as being in use, but actually contains no data. - The Scan Disk utility within Windows is designed to search for lost clusters and make them available to the file system again.



Solid State Drive (SSD)

An SSD does not have a Disk to read and write data, it instead relies on an embedded processor called a controller to perform operations related to reading and writing data. They are very similar to a USB flash drive.

System Storage – Hard Drives


PartitioningPartitioning is the process of electronically subdividing the physical hard drive into groups of cylinders called partitions.

A hard drive must have at least one partition, but may have many.

Each partition is assigned a drive letter. i.e. C: or D:

Primary Partitions = Bootable (Must be set Active).Extended Partitions = Non Bootable (Contain Logical Drives).



Partitioning



After partitioning you must format the drive before it becomes useable.

Formatting install a file system onto the partition.

File Systems are a method of organizing your files and folders onto the hard drive.

The File system tell the operating system where items are held so it can find them

System Storage – Data Storage (Page36)


Data can be held in 3 non-volatile ways

1) Magnetic Storage

2) Optical

3) USB

Method 1) Magnetic This method uses Magnetic disks and are either fixed or

removable. Examples of fixed are Hard Drive and removable are Floppy Disks

Method 2) Optical Drives This methods uses a laser to read a write data. Examples

include CD/DVD

Method 3) Flash Memory This method uses Flash memory . Examples include USB

thumb drives



Why can a Blu-Ray hold more information then a normal DVD?

DVD, DVD±R, DVD±RW, and DVD-RAM rely on a red laser to read and write data, the new format uses a blue-violet laser instead, hence the name Blu-ray.

The benefit of using a blue-violet laser is that it has a shorter wavelength than a red laser, which makes it possible to focus the laser spot with even greater

precision. This allows data to be packed more tightly and stored in less space, so it's possible to fit more data on the disc

BIOS – Flash Memory


Basic Input Output System• Firmware located on the Motherboard that is loaded when the computer is first switched on.• Identifies and checks the system hardware• Carries out POST (Power On Self Test)• Prepares a system to boot an Operating System.• Many types exist, Phoenix, Award, Ami , etc.• An example of a ROM (EEPROM)

Unified Extensible Firmware Interface(UEFI)


A replacement for the BIOS system, yet supports BIOS services.

UEFI is a specification detailing an interface that helps to hand off control of the system for the pre-boot environment (i.e.: after the system is powered on, but before the operating system starts).

Benefits include:• New authenticated boot scenarios• Support for new standard such as iPV6 (iPV6 network boot - iSCSI, PXE)• Improve boot graphics (Safe Mode Video)• New authenticated boot scenarios• 32-bit protected mode as being a native mode of operation– Support for > 2TB hard disk

RAID


Redundant Array of Independent Disks.

A System that employs two or more drives in combination for fault tolerance, performance or both.

RAID provides a method of accessing multiple individual disks as if the array were one larger disk.

RAID either spreads or duplicates the data across multiple disks, thereby either improving access time or reducing the risk of losing all data if one drive fails.

Typically RAID is used in large file servers, and application servers, where data accessibility is critical, and fault tolerance is required.

There are number of different RAID levels.

Investigate the RAID Layers



What 6 things could we attributes could we compare Hard Drive Disk and Solid State

Drives? Compare a similar sized SSD and HDD from an online retailer

Technology

m+storeMemory storage