Secondary Memory Transfer Time

Duration: 10 min

This video lesson is available to enrolled students.

Return to /learn/BPSC/computer-system-architecture/input-output-organisation/disk-structure-address/asset-secondary-memory-transfer-time after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About the Course: About the Course
  2. Section 1 | Language (Hindi): भाषा, लिपि, ध्वनि, वर्ण, अक्षर, स्वर, व्यंजन, मात्रा और संयुक्ताक्षर, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, विशेषण और क्रिया, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, संधि, समास, विलोम शब्द, पर्यायवाची शब्द, सामान्य अशुद्धियाँ, अनेक शब्दों के लिए एक शब्द, मुहावरे और लोकोक्तियाँ, अपठित गद्यांश और अपठित पद्यांश, Multi-Topic Content (Cross-Concept Material), वर्णमाला
  3. Section 1 | Language (उर्दू भाषा — 22 प्रश्न (निश्चित)): Spelling & Diacritics, Grammar (اسم, فعل, صفت, ضمیر), Vocabulary, Idioms & Proverbs, Comprehension
  4. Section 1 | Language (বাংলা / बांग्ला भाषा — 22 प्रश्न (निश्चित)): Bangla Script and Sounds, Bangla Grammar and Usage, Bangla Word Formation and Vocabulary, Reading and Text Interpretation
  5. Section 1 | Language (English): Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Pronoun, Verb, Adverb, Preposition, Articles, Determiner, Conjunction, Modals, Active Passive Voice (Voice), Direct and Indirect Speech, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Construction, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Verbal Analogy (Word Based Analogy), Facts, Inference and Judgements
  6. Section 2 | Primary Maths & Reasoning: Ratio and Proportion (Ratios), Divisibility Rules, Mixture and Alligation, Permutation and Combination, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Percentage, Average, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Mensuration and Geometry, Age Problems, Arithmetic, Powers and Exponents (Surds and Indices), Algebra, Probability, Trigonometry, Syllogisms, Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Venn Diagram, Data Arrangement, Inequality, Analogy, Ranking, Order and Sequence
  7. Section 2 | General Awareness (GK + Current Affairs): Polity, Physics, Biology, State Wise GK, Chemistry, History, Geography, Indian Economy, Environment, GK- Current Affairs, Static General Knowledge
  8. Section 3 | Computer System and Org. (CSO): Basics of COA, Floating Point Rep, Cache Memory Organization, Instr Formats & Modes, Programming the Basic Computer, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design
  9. Section 3 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, SQL, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control
  10. Section 3 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Process Synchronization
  11. Section 3 | Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics
  12. Section 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Shortest Path Algos
  13. Section 3 | Theory Of Computation & Compiler Design: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization
  14. Section 3 | Emerging Trends (AI, Societal Ethics & MS Office): Artificial Intelligence, Emerging Tech Trends, Society, Law & Ethics, MS Office Applications
  15. Section 3 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Maintenance and Configuration Management, Software Testing
  16. Section 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  17. Section 3 | OOPS, C++, JAVA, HTML: OOPS with C++, Java, HTML Basics, CSS
  18. Section 3 | Java: Java Fundamentals, Array, String, IO & References
  19. Section 3 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  20. Section 3 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  21. Section 3 | Multimedia: Multimedia
  22. BPSC Previous Year Papers:
  23. BPSC Full Mock Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a detailed lecture on the physical architecture of a Hard Disk Drive (HDD) and the mathematical calculation of data access time. The instructor begins by dissecting the HDD structure using a labeled diagram, explaining components like the spindle, platters, tracks, sectors, and cylinders. He then transitions to the performance metrics, defining the three primary components of access time: Seek Time, Rotational Latency, and Transfer Time. Through on-screen formulas, real-world images, and worked examples, the lecture guides students through the process of calculating the total time required to read or write data on a disk, a fundamental concept in computer organization.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a static schematic diagram of a Hard Disk Drive (HDD) structure, which serves as the primary visual aid. The instructor points out and explains key components labeled on the screen, including the central spindle, the circular platters stacked vertically, the arm assembly holding the read-write heads, and the concentric tracks. He explains that data is stored on these platters which rotate around the spindle. The diagram highlights specific areas like "track t" and "sector s", illustrating how a track is a circular path and a sector is a segment of that track. He also introduces the concept of a "cylinder c", which represents the set of tracks at the same radius across all platters. This section establishes the physical foundation necessary for understanding data access, ensuring students visualize the mechanical parts before moving to abstract timing concepts. The labels "platter", "rotation", and "arm" are clearly visible, guiding the viewer's attention to the moving parts.

  2. 2:00 – 5:00 02:00-05:00

    The lecture transitions to the concept of access time, specifically breaking down the "Total Transfer Time". The instructor displays the formula: Total Transfer Time = Seek Time + Rotational Latency + Transfer Time. He defines "Seek Time" as the time taken by the read/write header to reach the correct track, noting that this value is typically provided in exam questions. To make the concept concrete, he shows a photograph of an actual open hard disk drive, pointing out the physical arm and platters. He emphasizes that the arm assembly moves the read-write head radially across the platters to find the desired track, which constitutes the seek operation. The visual shift from diagram to real hardware helps bridge the gap between theoretical models and physical reality. The slide text explicitly states "Seek Time: - It is a time taken by Read/Write header to reach the correct track. (Always given in question)".

  3. 5:00 – 10:00 05:00-10:00

    The instructor delves deeper into the remaining components. He defines "Rotational Latency" as the time taken by the read/write header during the wait for the correct sector to rotate under the head. Since the starting position is random, he explains that for average analysis, we consider the time taken by the disk to complete half a rotation. He writes "R.L = 0" and "R.L = 1/2" to illustrate the range. Next, he defines "Transfer Time" as the time taken by the read/write header to either read or write data on a disk. He assumes that in one complete rotation, the header can read/write the entire track. He writes a formula on the screen: (F.S / T.S) * T(1 rev), where F.S is the file size and T.S is the track size. He provides a worked example, mentioning a scenario where a track holds 8MB and calculating the time for a 2MB transfer. This section is crucial for applying the concepts to numerical problems. The slide text for Transfer Time reads: "it is the time taken by read/write header either to read or write on a disk. In general, we assume that in 1 complete rotation, header can read/write the either track."

  4. 10:00 – 10:10 10:00-10:10

    The video concludes with a brief recap. The instructor reinforces the three components of access time. He reiterates that the total time is the sum of the time to seek the track, the time to wait for the sector, and the time to transfer the data. This final segment serves as a summary of the key formulas and concepts discussed throughout the lecture, ensuring students leave with a clear understanding of the total transfer time equation. The instructor is seen speaking directly to the camera, summarizing the points.

The video systematically builds an understanding of HDD mechanics and performance metrics. It starts with the physical layout (platters, tracks, sectors, cylinders) to establish where data resides. It then moves to the operational aspect, defining the three distinct time delays involved in accessing data: Seek Time (movement), Rotational Latency (waiting for rotation), and Transfer Time (actual data movement). By providing formulas and examples, the lecture equips students with the tools to calculate total access time, a critical concept in computer organization and architecture. The progression from physical structure to timing calculation provides a logical flow for learning.

Loading lesson…