Computer architecture forms the backbone of computer science. So, it comes as no surprise it’s one of the most researched fields of computing.


But what is computer architecture, and why does it matter?


Basically, computer architecture dictates every aspect of a computer’s functioning, from how it stores data to what it displays on the interface. Not to mention how the hardware and software components connect and interact.


With this in mind, it isn’t difficult to realize the importance of this structure. In fact, computer scientists did this even before they knew what to call it. The first documented computer architecture can be traced back to 1936, 23 years before the term “architecture” was first used when describing a computer. Lyle R. Johnson, an IBM senior staff member, had this honor, realizing that the word organization just doesn’t cut it.


Now that you know why you should care about it, let’s define computer architecture in more detail and outline everything you need to know about it.


Basic Components of Computer Architecture


Computer architecture is an elaborate system where each component has its place and function. You’re probably familiar with some of the basic computer architecture components, such as the CPU and memory. But do you know how those components work together? If not, we’ve got you covered.


Central Processing Unit (CPU)


The central processing unit (CPU) is at the core of any computer architecture. This hardware component only needs instructions written as binary bits to control all its surrounding components.


Think of the CPU as the conductor in an orchestra. Without the conductor, the choir is still there, but they’re waiting for instructions.


Without a functioning CPU, the other components are still there, but there’s no computing.


That’s why the CPU’s components are so important.


Arithmetic Logic Unit (ALU)


Since the binary bits used as instructions by the CPU are numbers, the unit needs an arithmetic component to manipulate them.


That’s where the arithmetic logic unit, or ALU, comes into play.


The ALU is the one that receives the binary bits. Then, it performs an operation on one or more of them. The most common operations include addition, subtraction, AND, OR, and NOT.


Control Unit (CU)


As the name suggests, the control unit (CU) controls all the components of basic computer architecture. It transfers data to and from the ALU, thus dictating how each component behaves.


Registers


Registers are the storage units used by the CPU to hold the current data the ALU is manipulating. Each CPU has a limited number of these registers. For this reason, they can only store a limited amount of data temporarily.


Memory


Storing data is the main purpose of the memory of a computer system. The data in question can be instructions issued by the CPU or larger amounts of permanent data. Either way, a computer’s memory is never empty.


Traditionally, this component can be broken into primary and secondary storage.


Primary Memory


Primary memory occupies a central position in a computer system. It’s the only memory unit that can communicate with the CPU directly. It stores only programs and data currently in use.


There are two types of primary memory:


  • RAM (Random Access Memory). In computer architecture, this is equivalent to short-term memory. RAM helps start the computer and only stores data as long as the machine is on and data is being used.
  • ROM (Read Only Memory). ROM stores the data used to operate the system. Due to the importance of this data, the ROM stores information even when you turn off the computer.

Secondary Memory


With secondary memory, or auxiliary memory, there’s room for larger amounts of data (which is also permanent). However, this also means that this memory is significantly slower than its primary counterpart.


When it comes to secondary memory, there’s no shortage of choices. There are magnetic discs (hard disk drives (HDDs) and solid-state drives (SSDs)) that provide fast access to stored data. And let’s not forget about optical discs (CD-ROMs and DVDs) that offer portable data storage.


Input/Output (I/O) Devices


The input/output devices allow humans to communicate with a computer. They do so by delivering or receiving data as necessary.


You’re more than likely familiar with the most widely used input devices – the keyboard and the mouse. When it comes to output devices, it’s pretty much the same. The monitor and printer are at the forefront.


Buses


When the CPU wants to communicate with other internal components, it relies on buses.


Data buses are physical signal lines that carry data. Most computer systems use three of these lines:


  • Data bus – Transmitting data from the CPU to memory and I/O devices and vice versa
  • Address bus – Carrying the address that points to the location the CPU wants to access
  • Control bus – Transferring control from one component to the other

Types of Computer Architecture


There’s more than one type of computer architecture. These types mostly share the same base components. However, the setup of these components is what makes them differ.


Von Neumann Architecture


The Von Neumann architecture was proposed by one of the originators of computer architecture as a concept, John Von Neumann. Most modern computers follow this computer architecture.


The Von Neumann architecture has several distinguishing characteristics:


  • All instructions are carried out sequentially.
  • It doesn’t differentiate between data and instruction. They’re stored in the same memory unit.
  • The CPU performs one operation at a time.

Since data and instructions are located in the same place, fetching them is simple and efficient. These two adjectives can describe working with the Von Neumann architecture in general, making it such a popular choice.


Still, there are some disadvantages to keep in mind. For starters, the CPU is often idle since it can only access one bus at a time. If an error causes a mix-up between data and instructions, you can lose important data. Also, defective programs sometimes fail to release memory, causing your computer to crash.


Harvard Architecture


Harvard architecture was named after the famed university. Or, to be more precise, after an IBM computer called “Harvard Mark I” located at the university.


The main difference between this computer architecture and the Von Neumann model is that the Harvard architecture separates the data from the instructions. Accordingly, it allocates separate data, addresses, and control buses for the separate memories.


The biggest advantage of this setup is that the buses can fetch data concurrently, minimizing idle time. The separate buses also reduce the chance of data corruption.


However, this setup also requires a more complex architecture that can be challenging to develop and implement.


Modified Harvard Architecture


Today, only specialty computers use the pure form of Harvard architecture. As for other machines, a modified Harvard architecture does the trick. These modifications aim to soften the rigid separation between data and instructions.


RISC and CISC Architectures


When it comes to processor architecture, there are two primary approaches.


The CISC (Complex Instruction Set Computer) processors have a single processing unit and are pretty straightforward. They tackle one task at a time. As a result, they use less memory. However, they also need more time to complete an instruction.


Over time, the speed of these processors became a problem. This led to a processor redesign, resulting in the RISC architecture.


The new and improved RISC (Reduced Instruction Set Computer) processors feature larger registers and keep frequently used variables within the processor. Thanks to these handy functionalities, they can operate much more quickly.


Instruction Set Architecture (ISA)


Instruction set architecture (ISA) defines the instructions that the processor can read and act upon. This means ISA decides which software can be installed on a particular processor and how efficiently it can perform tasks.


There are three types of instruction set architecture. These types differ based on the placement of instructions, and their names are pretty self-explanatory. For stack-based ISA, the instructions are placed in the stack, a memory unit within the address register. The same principle applies for accumulator-based ISA (a type of register in the CPU) and register-based ISA (multiple registers within the system).


The register-based ISA is most commonly used in modern machines. You’ve probably heard of some of the most popular examples. For CISC architecture, there are x86 and MC68000. As for RISC, SPARC, MIPS, and ARM stand out.


Pipelining and Parallelism in Computer Architecture


In computer architecture, pipelining and parallelism are methods used to speed up processing.


Pipelining refers to overlapping multiple instructions and processing them simultaneously. This couldn’t be possible without a pipeline-like structure. Imagine a factory assembly line, and you’ll understand how pipelining works instantly.


This method significantly increases the number of processed instructions and comes in two types:


  • Instruction pipelines – Used for fixed-point multiplication, floating-point operations, and similar calculations
  • Arithmetic pipelines – Used for reading consecutive instructions from memory

Parallelism entails using multiple processors or cores to process data simultaneously. Thanks to this collaborative approach, large amounts of data can be processed quickly.


Computer architecture employs two types of parallelism:


  • Data parallelism – Executing the same task with multiple cores and different sets of data
  • Task parallelism – Performing different tasks with multiple cores and the same or different data

Multicore processors are crucial for increasing the efficiency of parallelism as a method.


Memory Hierarchy and Cache


In computer system architecture, memory hierarchy is essential for minimizing the time it takes to access the memory units. It refers to separating memory units based on their response times.


The most common memory hierarchy goes as follows:


  • Level 1: Processor registers
  • Level 2: Cache memory
  • Level 3: Primary memory
  • Level 4: Secondary memory

The cache memory is a small and fast memory located close to a processor core. The CPU uses it to reduce the time and energy needed to access data from the primary memory.


Cache memory can be further broken into levels.


  • L1 cache (the primary cache) – The fastest cache unit in the system
  • L2 cache (the secondary cache) – The slower but more spacious option than Level 1
  • L3 cache (a specialized cache) – The largest and the slowest cache in the system used to improve the performance of the first two levels

When it comes to determining where the data will be stored in the cache memory, three mapping techniques are employed:


  • Direct mapping – Each memory block is mapped to one pre-determined cache location
  • Associative mapping – Each memory block is mapped to a single location, but it can be any location
  • Set associative mapping – Each memory block is mapped to a subset of locations

The performance of cache memory directly impacts the overall performance of a computing system. The following cache replacement policies are used to better process big data applications:


  • FIFO (first in, first out) ­– The memory block first to enter the primary memory gets replaced first
  • LRU (least recently used) – The least recently used page is the first to be discarded
  • LFU (least frequently used) – The least frequently used element gets eliminated first

Input/Output (I/O) Systems


The input/output or I/O systems are designed to receive and send data to a computer. Without these processing systems, the computer wouldn’t be able to communicate with people and other systems and devices.


There are several types of I/O systems:


  • Programmed I/O – The CPU directly issues a command to the I/O module and waits for it to be executed
  • Interrupt-Driven I/O – The CPU moves on to other tasks after issuing a command to the I/O system
  • Direct Memory Access (DMA) – The data is transferred between the memory and I/O devices without passing through the CPU

There are three standard I/O interfaces used for physically connecting hardware devices to a computer:


  • Peripheral Component Interconnect (PCI)
  • Small Computer System Interface (SATA)
  • Universal Serial Bus (USB)

Power Consumption and Performance in Computer Architecture


Power consumption has become one of the most important considerations when designing modern computer architecture. Failing to consider this aspect leads to power dissipation. This, in turn, results in higher operating costs and a shorter lifespan for the machine.


For this reason, the following techniques for reducing power consumption are of utmost importance:


  • Dynamic Voltage and Frequency Scaling (DVFS) – Scaling down the voltage based on the required performance
  • Clock gating – Shutting off the clock signal when the circuit isn’t in use
  • Power gating – Shutting off the power to circuit blocks when they’re not in use

Besides power consumption, performance is another crucial consideration in computer architecture. The performance is measured as follows:


  • Instructions per second (IPS) – Measuring efficiency at any clock frequency
  • Floating-point operations per second (FLOPS) – Measuring the numerical computing performance
  • Benchmarks – Measuring how long the computer takes to complete a series of test programs

Emerging Trends in Computer Architecture


Computer architecture is continuously evolving to meet modern computing needs. Keep your eye out on these fascinating trends:


  • Quantum computing (relying on the laws of quantum mechanics to tackle complex computing problems)
  • Neuromorphic computing (modeling the computer architecture components on the human brain)
  • Optical computing (using photons instead of electrons in digital computation for higher performance)
  • 3D chip stacking (using 3D instead of 2D chips as they’re faster, take up less space, and require less power)

A One-Way Ticket to Computing Excellence


As you can tell, computer architecture directly affects your computer’s speed and performance. This launches it to the top of priorities when building this machine.


High-performance computers might’ve been nice-to-haves at some point. But in today’s digital age, they’ve undoubtedly become a need rather than a want.


In trying to keep up with this ever-changing landscape, computer architecture is continuously evolving. The end goal is to develop an ideal system in terms of speed, memory, and interconnection of components.


And judging by the current dominant trends in this field, that ideal system is right around the corner!

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E-book: AI Agents in Education
OPIT - Open Institute of Technology
OPIT - Open Institute of Technology
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From personalization to productivity: AI at the heart of the educational experience.

Click this link to read and download the e-book.

At its core, teaching is a simple endeavour. The experienced and learned pass on their knowledge and wisdom to new generations. Nothing has changed in that regard. What has changed is how new technologies emerge to facilitate that passing on of knowledge. The printing press, computers, the internet – all have transformed how educators teach and how students learn.

Artificial intelligence (AI) is the next game-changer in the educational space.

Specifically, AI agents have emerged as tools that utilize all of AI’s core strengths, such as data gathering and analysis, pattern identification, and information condensing. Those strengths have been refined, first into simple chatbots capable of providing answers, and now into agents capable of adapting how they learn and adjusting to the environment in which they’re placed. This adaptability, in particular, makes AI agents vital in the educational realm.

The reasons why are simple. AI agents can collect, analyse, and condense massive amounts of educational material across multiple subject areas. More importantly, they can deliver that information to students while observing how the students engage with the material presented. Those observations open the door for tweaks. An AI agent learns alongside their student. Only, the agent’s learning focuses on how it can adapt its delivery to account for a student’s strengths, weaknesses, interests, and existing knowledge.

Think of an AI agent like having a tutor – one who eschews set lesson plans in favour of an adaptive approach designed and tweaked constantly for each specific student.

In this eBook, the Open Institute of Technology (OPIT) will take you on a journey through the world of AI agents as they pertain to education. You will learn what these agents are, how they work, and what they’re capable of achieving in the educational sector. We also explore best practices and key approaches, focusing on how educators can use AI agents to the benefit of their students. Finally, we will discuss other AI tools that both complement and enhance an AI agent’s capabilities, ensuring you deliver the best possible educational experience to your students.

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OPIT Supporting a New Generation of Cybersecurity Leaders
OPIT - Open Institute of Technology
OPIT - Open Institute of Technology
Aug 28, 2025 5 min read

The Open Institute of Technology (OPIT) began enrolling students in 2023 to help bridge the skills gap between traditional university education and the requirements of the modern workplace. OPIT’s MSc courses aim to help professionals make a greater impact on their workplace through technology.

OPIT’s courses have become popular with business leaders hoping to develop a strong technical foundation to understand technologies, such as artificial intelligence (AI) and cybersecurity, that are shaping their industry. But OPIT is also attracting professionals with strong technical expertise looking to engage more deeply with the strategic side of digital innovation. This is the story of one such student, Obiora Awogu.

Meet Obiora

Obiora Awogu is a cybersecurity expert from Nigeria with a wealth of credentials and experience from working in the industry for a decade. Working in a lead data security role, he was considering “what’s next” for his career. He was contemplating earning an MSc to add to his list of qualifications he did not yet have, but which could open important doors. He discussed the idea with his mentor, who recommended OPIT, where he himself was already enrolled in an MSc program.

Obiora started looking at the program as a box-checking exercise, but quickly realized that it had so much more to offer. As well as being a fully EU-accredited course that could provide new opportunities with companies around the world, he recognized that the course was designed for people like him, who were ready to go from building to leading.

OPIT’s MSc in Cybersecurity

OPIT’s MSc in Cybersecurity launched in 2024 as a fully online and flexible program ideal for busy professionals like Obiora who want to study without taking a career break.

The course integrates technical and leadership expertise, equipping students to not only implement cybersecurity solutions but also lead cybersecurity initiatives. The curriculum combines technical training with real-world applications, emphasizing hands-on experience and soft skills development alongside hard technical know-how.

The course is led by Tom Vazdar, the Area Chair for Cybersecurity at OPIT, as well as the Chief Security Officer at Erste Bank Croatia and an Advisory Board Member for EC3 European Cybercrime Center. He is representative of the type of faculty OPIT recruits, who are both great teachers and active industry professionals dealing with current challenges daily.

Experts such as Matthew Jelavic, the CEO at CIM Chartered Manager Canada and President of Strategy One Consulting; Mahynour Ahmed, Senior Cloud Security Engineer at Grant Thornton LLP; and Sylvester Kaczmarek, former Chief Scientific Officer at We Space Technologies, join him.

Course content includes:

  • Cybersecurity fundamentals and governance
  • Network security and intrusion detection
  • Legal aspects and compliance
  • Cryptography and secure communications
  • Data analytics and risk management
  • Generative AI cybersecurity
  • Business resilience and response strategies
  • Behavioral cybersecurity
  • Cloud and IoT security
  • Secure software development
  • Critical thinking and problem-solving
  • Leadership and communication in cybersecurity
  • AI-driven forensic analysis in cybersecurity

As with all OPIT’s MSc courses, it wraps up with a capstone project and dissertation, which sees students apply their skills in the real world, either with their existing company or through apprenticeship programs. This not only gives students hands-on experience, but also helps them demonstrate their added value when seeking new opportunities.

Obiora’s Experience

Speaking of his experience with OPIT, Obiora said that it went above and beyond what he expected. He was not surprised by the technical content, in which he was already well-versed, but rather the change in perspective that the course gave him. It helped him move from seeing himself as someone who implements cybersecurity solutions to someone who could shape strategy at the highest levels of an organization.

OPIT’s MSc has given Obiora the skills to speak to boards, connect risk with business priorities, and build organizations that don’t just defend against cyber risks but adapt to a changing digital world. He commented that studying at OPIT did not give him answers; instead, it gave him better questions and the tools to lead. Of course, it also ticks the MSc box, and while that might not be the main reason for studying at OPIT, it is certainly a clear benefit.

Obiora has now moved into a leading Chief Information Security Officer Role at MoMo, Payment Service Bank for MTN. There, he is building cyber-resilient financial systems, contributing to public-private partnerships, and mentoring the next generation of cybersecurity experts.

Leading Cybersecurity in Africa

As well as having a significant impact within his own organization, studying at OPIT has helped Obiora develop the skills and confidence needed to become a leader in the cybersecurity industry across Africa.

In March 2025, Obiora was featured on the cover of CIO Africa Magazine and was then a panelist on the “Future of Cybersecurity Careers in the Age of Generative AI” for Comercio Ltd. The Lagos Chamber of Commerce and Industry also invited him to speak on Cybersecurity in Africa.

Obiora recently presented the keynote speech at the Hackers Secret Conference 2025 on “Code in the Shadows: Harnessing the Human-AI Partnership in Cybersecurity.” In the talk, he explored how AI is revolutionizing incident response, enhancing its speed, precision, and proactivity, and improving on human-AI collaboration.

An OPIT Success Story

Talking about Obiora’s success, the OPIT Area Chair for Cybersecurity said:

“Obiora is a perfect example of what this program was designed for – experienced professionals ready to scale their impact beyond operations. It’s been inspiring to watch him transform technical excellence into strategic leadership. Africa’s cybersecurity landscape is stronger with people like him at the helm. Bravo, Obiora!”

Learn more about OPIT’s MSc in Cybersecurity and how it can support the next steps of your career.

Read the article