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.