Managing
Storage
devices:Know
about
Semiconductor Memories – RAM, ROM on System
Board, Main Memory – SIMMs, DIMMs, Other RAM
Technologies, Hard drives – hard drive technology –
IDE, EIDE, SCSI, SATA, Hard drive partitions, Troubleshooting hard drives & data recovery, Optimizing Hard
drive – disk clean-up, disk fragmentation. Disk backup.
Semiconductor Memory:
• A device which is used to stores digital information is known as
semiconductor memory.It is also known as memory chip,
semiconductor storage or transistor memory.
• The semiconductor memory is directly accessible by the
microprocessor. It offers high operating speed and has the
ability to consume low power.
• It fabricated as IC’s thus it requires less space inside the system.
The fabrication of semiconductor memories is done through
CMOS technology.
• The access time of these memory must be compatible with the
microprocessor. Thus semiconductor devices are preferred as
primary memory.
There are two types of semiconductor memory :
1. Volatile
2. Non-volatile
Volatile memory:
• Volatile memories are those memories that store the data
temporarily.
• We can say that data is stored in volatile memory only till the
duration power supply is ON. Once the supply gets OFF then the
stored data gets lost.
Example: RAM is a volatile memory.
Types of Semiconductor memory
1. Volatile
2. Non Volatile
Random Access Memory (RAM) :
• It is also knows as working memory of computer. The Read and
write (R/W) memory of a computer is called RAM.
• The User can write information to it and read information from
it.
• RAM is a volatile memory, it means information written to it can
be accessed as long as power is on.
• RAM holds data and processing instructions temporarily.
There are two types of RAM:
1. SRAM
2. DRAM
What are the common types of DRAM?
1. SDRAM - Synchronous DRAM
2. RDRAM - Rambus DRAM
3. DDR SDRAM - Double Data Rate SDRAM
Note : DDR1 SDRAM has been succeeded by DDR2, DDR3, and most
recently, DDR4 SDRAM.
Difference between Static RAM and Dynamic RAM
SRAM
DRAM
It stores information as It stores information as long as the
long as the power is power is supplied or a few milliseconds
supplied.
when the power is switched off.
SRAM
DRAM
Transistors are used to
Capacitors are used to store data in
store information in
DRAM.
SRAM.
Capacitors are not used To store information for a longer time,
hence no refreshing is the contents of the capacitor need to be
required.
refreshed periodically.
SRAM is faster compared
DRAM provides slow access speeds.
to DRAM.
It does not have a
It has a refreshing unit.
refreshing unit.
These are expensive.
These are cheaper.
SRAMs are low-density
DRAMs are high-density devices.
devices.
In this bits are stored in In this bits are stored in the form of
voltage form.
electric energy.
These are used in cache
These are used in main memories.
memories.
Consumes less power Uses more power and generates more
and generates less heat. heat.
SRAM
DRAM
SRAMs has lower latency
DRAM has more latency than SRAM
SRAMs
are
more
DRAMs are less resistant to radiation
resistant to radiation
than SRAMs
than DRAM
SRAM has higher data
DRAM has lower data transfer rate
transfer rate
SRAM is used in high- DRAM is used in lower-speed main
speed cache memory
memory
SRAM is used in high
DRAM is used in general purpose
performance
applications
applications
Non-volatile memory:
• Non-volatile memories are those memories that store the data
permanently.
• The data retained in the memory even if the power supply is OFF.
• ROM is a non-volatile memory.
ROM:
• It stands for Read-Only Memory.
• ROM is an example of nonvolatile memory.
• It is a memory array that is permanently programmed by the
programmer only once.
• User can not be changed or modify ROM data only read. Hence
its data cannot be changed by the processor once it is
programmed.
There are various types of ROM:
1. PROM
2. EPROM
3. EEPROM
PROM :
• It stands for Programmable Read Only Memory.
• It is a semiconductor memory which can only have data written
to it once.
• Once the PROM is programmed, the information written is
permanent and cannot be erased or deleted.
• PROM was first developed by Wen Tsing Chow in 1956.
• An example of a PROM is a computer BIOS in early computers.
• Today, PROM in computers has been replaced by EEPROM.
Note : PROM is also called a FPROM (field PROM) or OTP (one-time
programmable) chip.
EPROM:
• It stands Erasable Programmable Read-Only Memory. EPROM
was the replacement for ROM and PROM.
• It was developed to overcome the disadvantages of ROM and
PROM.
• EPROM is a non-volatile memory.
• EPROM is developed by Dov Frohman in 1971 at Intel.
• EPROM is a type of ROM chip that can retain the data even if
there is no power supply.
• The data can be erased and reprogrammed by using ultraviolet
(UV) light. The process of programming an EPROM is often
called BURNING.
• Nowadays EPROM chips are not used in the computer, and these
EPROM chips replaced by EEPROM.A programmed EPROM can
retain its data for a minimum of 10 to 20 years.
EEPROM:
• It stands for electrically erasable programmable read-only
memory.
• It is a non-volatile ROM chip which is used for storing a small
amount of data in computers. In EEPROM, the data is erased
using an electrical signal.
• EEPROM was developed by George Perlegos in 1978 at Intel.
• EEPROM used as a replacement for PROM and EPROM. Here,
erase and write operations are performed by byte per byte.
• We can reprogram EEPROM infinite number of times. We can
program and erase the contents of EEPROM without removing
the chip from the computer.
Flash Memory:
• Flash memory combines the advantages of ROM and RAM. It
can be written or programmed in units called “Sector” or a
“Block.”
• Flash Memory is EEPROM means that it can retain its contents
when the power supply removed. It commonly found in mobile
phones, USB flash drives, tablet computers, and embedded
controllers.
• Flash memory is often used to hold control code such as the BIOS
in a personal computer. This memory is used in USB, SD card,
memory chip etc.
.
SIMM (Single In-line Memory Module)
•
A type of memory module containing random-access
memory (RAM) used in computers from the early 1980s
to the early 2000s.
•
SIMMs have a single row of electrical contacts on one
side of the module.
•
SIMMs are typically 30-pin or 72-pin modules.
•
30-pin SIMMs are used in 8-bit and 16-bit computers,
such as the IBM XT and AT.
•
72-pin SIMMs are used in 32-bit computers, such as the
486 and early Pentium systems.
•
SIMMs are installed in pairs in memory sockets on the
motherboard.
•
SIMMs were superseded by DIMMs (dual in-line memory
modules) in the late 1990s.
Important points about SIMMs
•
SIMMs are older technology than DIMMs.
•
SIMMs are not as widely available as DIMMs.
•
SIMMs are not as fast as DIMMs.
•
SIMMs are not as reliable as DIMMs.
Uses of SIMMs
•
SIMMs can be used to upgrade older computers.
•
SIMMs can be used to repair older computers.
•
SIMMs can be used for educational purposes.
Comparison of SIMMs and DIMMs
Feature
SIMM
DIMM
Number of contact 1
rows
2
Pin count
30 or 72
168, 184, 200, or
240
Data width
8 or 32 bits
64 bits
Speed
Slower
Faster
Reliability
Less reliable More reliable
Availability
Less
available
More available
DIMM (Dual In-Line Memory Module)
DIMM (Dual In-line Memory Module) is a type of random access
memory (RAM) module that is used in personal computers,
workstations, servers, and other devices. DIMMs are typically long,
thin circuit boards that contain one or more RAM chips. The chips are
arranged in rows on the circuit board, and they are connected to the
motherboard by a series of pins.
Important points about DIMMs:
• DIMM stands for Dual In-Line Memory Module.
▪ Current memory modules come in DIMMs.
▪ "Dual in-line" refers to pins on both sides of the
modules.
A DIMM had a 168-pin connector
supporting 64-bit data bus, which is twice the data
width of SIMMs.
▪ The wider bus means, more data can pass through a
DIMM, translating to faster overall performance.
▪ Latest DIMMs based on fourth-generation double
data rate (DDR4) SDRAM have 288-pin connectors for
increased data throughput
• DIMMs are natively 64-bit, meaning they can transfer data 64
bits at a time. This is in contrast to SIMMs (Single In-line Memory
Modules), which are 32-bit.
• DIMMs are available in a variety of speeds, measured in
megahertz (MHz). The higher the speed, the faster the DIMM
can transfer data.
• DIMMs are also available in a variety of capacities, measured in
gigabytes (GB). The higher the capacity, the more data the DIMM
can store.
• DIMMs are typically installed in pairs or in groups of four. This is
because most motherboards have multiple memory channels.
By installing DIMMs in pairs or in groups of four, the memory
bandwidth is increased.
• The memory chips of DIMM are DRAM (Dynamic Random Access
Memory), which is the most common category of main memory.
Uses of DIMMs:
•
DIMMs are used to store data that is being actively used by the
computer. This includes data for the operating system,
applications, and documents.
•
DIMMs are also used to store data that is being transferred
between the computer and other devices. For example, when
you copy a file from a USB flash drive to your computer, the data
is first stored in DIMM.
•
DIMMs are essential for the proper functioning of a computer.
Without DIMMs, the computer would not be able to store data
or run applications.
Types of DIMMs:
•
UDIMMs (Unbuffered DIMMs): These are the most common
type of DIMM. They are used in most desktop and laptop
computers.
•
RDIMMs (Registered DIMMs): These DIMMs include a register
that helps to improve signal integrity. They are typically used in
servers and workstations.
•
FB-DIMMs (Fully Buffered DIMMs): These DIMMs include a
buffer that helps to improve performance. They are typically
used in high-end servers.
•
LR DIMMs (Load-Reduced DIMMs): These DIMMs are designed
to reduce the load on the memory controller. They are typically
used in servers with a large number of DIMMs.
Conclusion
DIMMs are an essential component of modern computers. They
provide the storage space that is needed to run applications and store
data. DIMMs are available in a variety of speeds and capacities to
meet the needs of different users.
What is HDD ?
• HDD (Hard Disk Drive) is a data storage device that uses
magnetic storage to store and retrieve digital data .
• HDD stands for hard disk drive.
• It is a non-volatile hardware component on a computer.
• A hard drive acts as the storage for all digital content.
• It holds program files, documents, pictures, videos, music, and
more.
• The non-volatile nature of hard drives means they don’t lose
data, even if power is lost.
• Due to this, they help computers store files and other data for a
long time – as long as they don’t get damaged or corrupted.
• The HDD was introduced in the year 1956 by IBM.
Hard Drive Technology :
o
o
o
o
IDE
EIDE
SCSI
SATA
1.IDE( Integrated Drive Electronics)
IDE stands for Integrated Drive Electronics. It is a standard
interface used for connecting motherboard to storage devices
like Hard Discs, CD-ROM/ DVD Drives, HDD etc
Important points about IDE:
•
IDE was a parallel interface, meaning that data was transferred
between the storage device and the motherboard 16 bits at a
time.
•
IDE supported two devices per channel, for a total of four
devices per motherboard.
•
IDE devices were limited to a transfer rate of 133 MB/s.
Uses of IDE:
•
IDE was the most common interface for connecting storage
devices to computers for many years.
•
IDE devices were relatively inexpensive and easy to install.
•
IDE devices were compatible with a wide variety of
motherboards.
2.EIDE (Enhanced Integrated Drive Electronics)
EIDE (Enhanced Integrated Drive Electronics) is a hard drive interface
that was developed in the early 1990s. It is an improvement over the
older IDE (Integrated Drive Electronics) interface, and it offers a
number of advantages, including:
•
Increased data transfer rates: EIDE hard drives can transfer data
at rates of up to 133 megabytes per second (MB/s), compared
to 16.6 MB/s for IDE hard drives.
•
Larger storage capacities: EIDE hard drives can have capacities of
up to 137 gigabytes (GB), compared to 8.4 GB for IDE hard drives.
•
Support for multiple devices: EIDE can support up to four hard
drives on a single controller, compared to two hard drives for
IDE.
Important points about EIDE:
•
EIDE is also known as ATA-2 (Advanced Technology Attachment2).
•
EIDE is backward compatible with IDE, so IDE hard drives can be
used in EIDE controllers.
•
EIDE was superseded by the Ultra ATA/ATA-6 interface in the
late 1990s.
•
The term was coined by Western Digital in 1994.
Uses of EIDE:
•
EIDE hard drives were used in personal computers, workstations,
and servers.
•
EIDE hard drives were used to store all types of data, including
documents, pictures, music, videos, and applications.
•
EIDE hard drives were used to back up data from other storage
devices.
2.SCSI (Small Computer System Interface)
SCSI (Small Computer System Interface) is a set of standards for
physically connecting and transferring data between computers and
peripheral devices, such as hard disk drives (HDDs). SCSI was
introduced in the 1980s and has seen widespread use on servers and
high-end workstations.
Important points about SCSI HDDs:
•
SCSI HDDs offer higher performance than other types of HDDs,
such as PATA (Parallel ATA) and SATA (Serial ATA).
•
SCSI HDDs can support more devices on a single bus than other
types of HDDs.
•
SCSI HDDs are more expensive than other types of HDDs.
•
SCSI HDDs are typically used in high-performance applications,
such as servers, workstations, and video editing systems.
•
Connections through SCSI on personal computers have now
been replaced by the USB.This means that SCSI is no longer used
as consumer hardware.
Uses of SCSI HDDs:
•
Servers: SCSI HDDs are used in servers to provide highperformance storage for applications such as databases, web
servers, and email servers.
•
Workstations: SCSI HDDs are used in workstations to provide
high-performance storage for applications such as video editing,
CAD/CAM, and scientific computing.
•
Video editing systems: SCSI HDDs are used in video editing
systems to provide high-performance storage for large video
files.
•
RAID (Redundant Array of Independent Disks) configurations:
SCSI HDDs are used in RAID configurations to improve
performance and reliability.
3.SATA(Serial Advanced Technology Attachment)
Serial ATA or SATA is a computer bus interface for connecting the
storage disks or drives to the motherboard of computer systems. SATA
standards help in transferring data from hard drives and optical disk
drives to computer systems.
Important points about SATA:
•
SATA is the standard interface for connecting hard drives to
computers. SATA offers a number of advantages over PATA,
including faster data transfer rates, thinner and more flexible
cables, and hot-pluggable devices. SATA hard drives are a good
choice for general-purpose storage
•
SATA uses a serial interface to transfer data, which is faster and
more efficient than the parallel interface used by PATA.
•
SATA supports higher data transfer rates than PATA. The latest
SATA revision, SATA III, supports data transfer rates of up to 6
Gbit/s.
•
SATA cables are thinner and more flexible than PATA cables,
making them easier to install.
•
SATA devices are hot-pluggable, meaning they can be added or
removed from a computer without having to shut down the
computer.
Uses of SATA in hard drives:
•
SATA is the standard interface for connecting hard drives to
computers.
•
SATA hard drives are available in a variety of capacities, from a
few hundred gigabytes to several terabytes.
•
SATA hard drives are relatively inexpensive compared to other
types of storage devices, such as SSDs.
•
SATA hard drives are a good choice for general-purpose storage.
Advantages of SATA over PATA:
•
Faster data transfer rates
•
Thinner and more flexible cables
•
Hot-pluggable devices
•
More efficient use of bandwidth
Disadvantages of SATA over PATA:
•
SATA devices are not as widely compatible as PATA devices.
•
SATA cables can be more expensive than PATA cables.
Hard drive partitions:
•
A hard drive partition is a logical division of a hard disk drive
(HDD) that is treated as a separate unit by operating systems
(OSes) and file systems. The OSes and file systems can manage
information on each partition as if it were a distinct hard drive.
•
For example, a hard drive can be partitioned into two partitions,
one for the operating system and one for user data. This allows
the operating system to be installed on one partition and user
data to be stored on the other partition. If the operating system
becomes corrupted, the user data can be saved by reinstalling
the operating system on the first partition.
•
Partitions can also be used to create multiple bootable operating
systems on a single hard drive. This allows users to boot into
different operating systems without having to change the hard
drive.
Types of hard drive partitions:
•
Primary partitions: A primary partition is a bootable partition
that can contain an operating system. A hard drive can have up
to four primary partitions.
•
Extended partitions: An extended partition is a non-bootable
partition that can be divided into multiple logical drives. A hard
drive can have one extended partition in addition to four primary
partitions.
•
Logical drives: A logical drive is a division of an extended
partition that is treated as a separate unit by the operating
system. A hard drive can have up to 128 logical drives.
Benefits of partitioning a hard drive:
•
Improved data organization: Partitioning a hard drive can help to
improve data organization by separating different types of data
onto different partitions. This can make it easier to find and
manage data.
•
Increased security: Partitioning a hard drive can help to increase
security by isolating sensitive data on a separate partition. This
can make it more difficult for unauthorized users to access
sensitive data.
•
Easier troubleshooting: Partitioning a hard drive can make it
easier to troubleshoot problems. If a problem occurs with one
partition, the other partitions can be unaffected. This can make
it easier to identify and fix the problem.
•
More efficient use of space: Partitioning a hard drive can help to
make more efficient use of space. By creating multiple partitions,
users can ensure that each partition is used for its intended
purpose.
Trouble-shooting hard drives & data recovery
Troubleshooting:
•
Troubleshooting is the process of identifying and resolving
problems. It involves a series of steps that are taken to diagnose
the cause of a problem and then to find a solution.
•
It is the process of identifying a common error or fault within a
software or computer system. It enables the repair and
restoration of a computer software when it becomes faulty,
unresponsive or acts in an abnormal way.
We troubleshoot due to the following system faults:
•
Identify the problem: The first step is to identify the problem
with the hard drive. This can be done by listening for unusual
noises, checking for error messages, or running diagnostic tests.
•
Check for physical damage: If the hard drive has been physically
damaged, it may not be possible to recover the data. However,
if the damage is minor, it may be possible to repair the drive and
recover the data.
•
Try a different power supply or cable: Sometimes, a problem
with the power supply or cable can cause the hard drive to
malfunction. Try using a different power supply or cable to see if
this resolves the issue.
•
Update the firmware: Sometimes, a problem with the hard drive
firmware can cause problems. Check the manufacturer's website
for firmware updates and install them if necessary.
•
Run diagnostic tests: Most hard drive manufacturers provide
diagnostic tools that can be used to check the health of the drive.
Run these tests to see if they identify any problems.
•
How to Troubleshoot Hard Disk:
1.
2.
3.
4.
5.
6.
Open File Explorer and find the disk which has problems.
Right click on the hard disk with errors.
Choose Properties.
Navigate to Tools bar in the Properties window.
Click on the Check button.
Select Scan and repair drive to start detecting & fixing disk
errors.
Data recovery
•
Data recovery is the process of retrieving data from a storage
device that has been damaged or corrupted. There are a number
of different data recovery methods, and the best method will
depend on the specific circumstances.
•
Some common data recovery methods include:
o
Software recovery: This method uses software to scan the
storage device for lost or corrupted data.
o
Hardware recovery: This method involves physically
opening the storage device and repairing any damage.
o
Cloud recovery: This method uses cloud-based services to
recover data from a damaged or corrupted storage device.
Recover Data from a Corrupted or Crashed Hard Drive with Software:
•
Disk Drill is a data recovery tool that facilitates easy recovery of
your essential documents,
photos, videos, and other related data lost from a variety of
storage devices.
Optimizing Hard drive
•
Optimizing a drive is the process of improving its performance
and efficiency.
•
Optimizing the disk means that it compresses and organizes the
files on your hard disk.
•
Optimizing your drives can help your PC run smoother and boot
up faster.
•
To optimize them:
o Select the search bar on the taskbar and enter defrag.
o Select Defragment and Optimize Drives.
o Select the disk drive you want to optimize.
o Select the Optimize button.
•
Optimizing a drive can help to improve its performance and
efficiency. This can lead to a number of benefits, such as:
•
Faster boot times
•
Reduced loading times for applications and games
•
Improved overall system responsiveness
Disk cleanup
•
•
•
•
•
Disk Cleanup is a utility software included in Microsoft Windows
that helps users free up disk space by removing unnecessary
files. These files can include temporary files, cached webpages,
and rejected items that end up in the Recycle Bin.
First introduced with Windows 98 and included in all subsequent
releases of Windows.
It allows users to remove files that are no longer needed or that
can be safely deleted.
Removing unnecessary files, including temporary files, helps
speed up and improve the performance of the hard drive and
computer
Running Disk Cleanup at least once a month is an excellent
maintenance task and frequency.
Steps to Delete the Temporary Files Using Disk Cleanup:
1. Open the search box from the taskbar in your system, and search
for Disk Cleanup. Select Disk Cleanup from the list of programs.
This will open the utility software in the system.
2. You will see the list of drives, select the drive you want to clean
and then click OK.
3. This will open the files occupying the drive in the system from
the list of files that can be deleted. The user can select the files
they want to remove. If the user wants a description of the file
type, select the file.
4. Once the user has selected all the files, click on OK.
•
It is an effective and economical solution with a straight forward
interface for beginners.
Steps :
1. Download and Install Disk Drill for Windows or Mac OS.
2. Launch Disk Drill recovery software, select the crashed hard disk and
click:
3. Preview the files you found with Quick or Deep Scan. Disk Drill
provides you with a complete disk scan
report at the end of the recovery operation.
5.Click Recover to recover your lost data.
Disk backup:
• Hard disk backup is a process to create a complete copy of
everything in a hard drive to another HDD/SSD or an external
hard drive
• With a hard disk backup, you can fully protect your computer
data from the following disasters:
o Virus attack
o Accidental deletion
o Careless formatting
o Hard drive corrupted
o OS crash or boot issue
Disk fragment
A disk fragment is a piece of a file that is not stored in contiguous
blocks on a disk. This can happen over time as files are created,
deleted, and modified. As a result, the disk has to work harder
to find and read the different pieces of a file, which can slow
down your computer's performance.
For example, imagine a picture file that is saved to your hard
drive. When you first save the file, it is stored in a single
contiguous block on the disk. However, over time, as you delete
and modify other files, the empty blocks on the disk are reused
to store new files. This can lead to the picture file being split up
into multiple fragments, which are scattered across the disk.
•
•
•
Disk fragmentation can cause a number of problems, including:
Slow performance
Increased wear and tear on the disk drive
Increased risk of data corruption
There are three main types of fragmentation:
•
Internal fragmentation: This occurs when a file is allocated more
disk space than it needs. The unused space is wasted and cannot
be used by other files.
For example, if a file system uses 4KB blocks, and a file is 1KB in
size, the operating system will still allocate 4KB of disk space to
the file. This results in 3KB of wasted space
•
External fragmentation: This occurs when there is enough free
disk space to store a file, but the space is not contiguous. As a
result, the file has to be split up into multiple blocks, which are
scattered across the disk.
•
Data fragmentation: This occurs when a file is stored in noncontiguous blocks on disk. This can happen when the file is
created, modified, or deleted.
Defragmentation:
Defragmentation is a process that reorganizes the files on your
disk to make them contiguous. This can improve performance
and reduce wear and tear on your disk drive
You can use the built-in Disk Defragmenter tool in Windows to
defragment your disk.
o open the Start menu and search for "Disk Defragmenter".
o Then, select the disk you want to defragment and click the
"Analyze" button.
o Once the analysis is complete, click the "Defragment"
button to start the defragmentation process.