Central processing units (CPUs) are the brain of our computers. They process everything we do every day, from opening the application to watching a movie. But what exactly is a CPU? How does it work? And what is the difference between CPUs and the more popular vCPU?
Understanding the Brain in Computers
The first electronic computers were invented in the early 1800s, according to the complete history guide published by G2. However, these computers are large and expensive, and they can only be used by trained mathematicians and scientists.
Charles Babbage was credited with inventing the first computer engine, the Difference Engine, which could be programmed to perform any calculation that could be done by hand. However, the Difference Engine project was not completed due to lack of funding, according to the Computer History Museum.
In 1937, Babbage first mentioned the Analytical Engine, which would become the first mechanical computer in the world. “The Analytical Engine includes all the elements of a modern-day computer: an arithmetic logic unit, flow control in the form of conditional branching and loops, and integrated memory,” (Electronics Notes).
An important part of the computer today is the CPU or central processing unit. The CPU is responsible for executing the instructions it gives to the software such as the operating system or application. In layman’s terms, you can think of the CPU as the brain of your computer. The CPU consists of two main parts: the control unit and the arithmetic logic unit (ALU). If these abbreviations confuse you, check out our overview of how APUs, CPUs, and GPUs differ.
The control unit is responsible for retrieving instructions from memory, decoding them, and then sending them to the arithmetic logic unit to execute. The ALU performs arithmetic and logical operations on data stored in registers, which are internal storage units within the CPU.
Modern CPUs also have a cache, which is a small amount of high-speed memory that stores frequently used instructions and data. Caches are divided by level; The Level 1 (L1) cache is built into the CPU die itself, the Level 2 (L2) cache sits on a separate chip near the CPU, and the Level 3 (L3) cache sits farther away from the CPU itself chip or even. own circuit board.
CPU versus vCPU
With the rise of cloud services came the advent of the virtual central processing unit, or vCPU for short. TechTarget defines a vCPU as “a physical central processing unit (CPU) assigned to a virtual machine (VM).”
Virtual machines basically have their own operating systems that run inside another operating system like applications. VMs are used for a variety of purposes such as testing new software in a secure environment, running multiple operating systems (for example, Windows and Linux) on the same computer, or consolidating multiple physical devices. server to a server to save space and reduce cost.
Thus, vCPU is a software implementation of a CPU; it is not physically present inside your computer like a real CPU. The hypervisor, which is the software that creates and manages the VMs, assigns vCPUs to the virtual machine. Each vCPU appears in the operating system within the VM as a true CPU core. See our explanation of hypervisors to learn more.
However, because vCPUs are software-based, they are not as efficient as real CPUs. Therefore, it is important to specify how many cores your processor has when you buy a computer (for example, “quad-core” means four cores). The same rule applies when choosing a virtual private server (VPS) or dedicated server hosting plan.
The main difference between CPUs and vCPUs is that CPUs are hardware -based while vCPUs are software -based. This means that the CPUs are physically present in your computer while the vCPUs are not; however, they are performed by hypervisors when necessary. Because of this difference in implementation, CPUs are more efficient than vCPUs; they have no overhead associated with running the software.
Since the early 2000s, vCPUs have become more popular because they are cheaper and easier to assign than physical CPUs; however, if you are looking for performance, it is best to use a computer with multiple CPU cores because each core can process instructions independently.
Cores vs. Threads
A CPU can have one or more cores, which is the processing unit that performs tasks at a specific time. The core will maintain the task execution sequence, the registers, and the cache (if possible) and perform operations through the ALU. The CPU controls the cores, but the core executes every software process or thread scheduled by the operating system. A string is an independent sequence of instructions that can be processed by a CPU.
Multiple threads can exist within the same process and share the same memory space. This allows them to communicate with each other more easily than if they were running through different processes. Threads are commonly used to improve the performance of multithreaded applications by allowing different parts of the program to simultaneously run on different cores or processors.
The term “thread” has been used to compute terminology for many years; however, in the early 2000s that level of hardware support for wires was introduced by processors. This allows multiple threads to be created simultaneously on different cores. Previously, only one string could be executed at a time in a core, regardless of how many cores there were in the processor. Multicore processors are more common, and most operating systems provide some level of support for running programs as multiple threads.
Concluding Key Issues
In summary, CPUs are the hardware-based brains of our computers, while their virtual counterparts, vCPUs, are software-based and are created by hypervisors to run within virtual machines. Cores are hardware -based processing units within a CPU, while cores are software -based instructions that can be processed by a CPU.
The strings can be simultaneously executed on separate cores, allowing different parts of the program to run at the same time. This can improve hardware performance because multiple tasks can be processed simultaneously instead of sequentially.
Now that you understand the difference between CPUs, vCPUs, cores, and threads, you can make an informed decision in choosing a computer or server. If you are looking for performance, it is best to choose a computer with multiple CPU cores because each core can process instructions independently. However, if you’re looking for a cost-effective solution, vCPUs might be the way to go.