CPU – the “heart of every computer” explained simply

The abbreviation CPU stands for “Central Processing Unit” and means something like “central processing unit”. The CPU is the main processor that forms the core of every computer. Only with this central processing unit can the computer process important commands, control the flow of data or coordinate various processes in the system. The CPU is therefore responsible for all calculations and the functioning of the PC. For this reason, it is often referred to as the “heart” or “brain” of a computer.

STACKIT is a German cloud service provider that offers secure, GDPR-compliant cloud and IT solutions from German and Austrian data centers. STACKIT provides virtualized virtual machines and CPU resources so that customers can use flexible and scalable computing power for their cloud applications. Originally developed for internal use within the Schwarz Group, STACKIT now offers flexible IT solutions externally. With its targeted focus on European data sovereignty and independence from global providers, STACKIT aims to make a significant contribution to a digital ecosystem for growth and innovation in Europe.

Explanation of the most important terms relating to CPU

• CPU (Central Processing Unit): Central processing unit (processor) of a computer, often referred to as the “heart” or “brain”. It performs all basic calculations and control tasks by executing all commands and coordinating the data flow.
• Cache: Particularly fast intermediate memory within the CPU. The cache stores frequently used instructions and data so that the CPU can access them more quickly without having to fetch them from the slower main memory (RAM) each time. This speeds up processing and increases the overall performance of the processor.
• Transistors: Tiny electronic switches that are built into a processor in their billions. They control the flow of electrical current and thus form the basis for all computing operations. The more transistors a processor has, the more powerful and complex it can be.
• Ryzen: Brand name of a modern processor family from AMD. These CPUs are known for their efficiency and performance – for desktop PCs as well as laptops and server applications. In addition, the AMD Ryzen processor family is valued for its good price-performance ratio and competes directly with Intel’s Core processors.
• Core: Independent computing core (processor core) within a processor. A CPU consists of several cores that can process tasks independently of each other. A modern multi-core processor therefore has more cores and thus increases the multitasking capability and overall performance of the processor. An example of this is a quad-core processor with four cores.
• Thread: An execution unit within a process. A process can have several threads that perform different tasks at the same time. Modern CPUs with HyperThreading (Intel) or simultaneous multithreading technologies (e.g. AMD) can process several threads in parallel per physical processor core, which significantly increases efficiency and CPU utilization as idle times are reduced.
• Hypervisor: Software that makes it possible to operate several virtual machines (VMs) on one physical hardware. It manages the allocation and execution of resources such as CPU, RAM and memory to the individual virtual machines and ensures their isolation.
• vCPU (virtual CPU): Virtual, software-based central processing unit for virtual machines provided by the hypervisor. It is assigned to a virtual machine and is based on the host’s physical processor cores and threads. The hypervisor handles the exact vCPU assignment flexibly and dynamically.
• Processor virtualization: Technology that allows CPU instructions from virtual machines to be executed directly on the hardware. New CPUs from Intel and AMD support this on the hardware side, which increases efficiency and security. This allows multiple operating systems and applications to run independently of each other on the same hardware.
• Overcommit/overbooking: More virtual resources (e.g. vCPUs or RAM) are allocated to virtual machines than there are actual physical cores available. This is possible because not all virtual machines need their full performance at the same time. It increases utilization, but can lead to performance losses under high load.
• IOMMU (Input/Output Memory Management Unit): Hardware component that manages inputs and outputs (input/output) between devices and memory. It enables the assignment of devices to virtual machines (device passthrough) and protects the memory from unauthorized access.
• Partitioning: Division of resources such as memory, hard disks or CPU into several independent areas, which can then be assigned to several VMs, for example.
• Flavors: Predefined configurations for virtual machines in the cloud computing web. A flavor determines how many virtual CPUs, how much RAM (working memory) and how much storage space (e.g. hard disk capacity) is assigned to a virtual machine. When you create a new VM, you select a flavor that meets your individual requirements, such as “small” (low CPU and RAM) or “large” (high CPU and RAM). In this way, resources can be distributed efficiently and optimally for various applications.

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What are the advantages of CPU with STACKIT?

CPU utilization with STACKIT offers various advantages:

What exactly is the CPU?

The CPU – Central Processing Unit – is the core of a computer and performs all basic computing operations. In virtualized environments, the computing power of a physical CPU is divided into several virtual CPUs (vCPUs) with the help of a hypervisor, which can then be assigned to individual virtual machines. A modern processor from Intel or AMD has special functions for hardware-based virtualization so that several virtual machines can be operated efficiently and securely on one host at the same time.

Virtualization technology ensures that each virtual machine works in isolation and can use the resources assigned to it flexibly. For maximum performance and a high level of security, it is important that the CPU, BIOS and mainboard support important virtualization functions such as Intel VT-x or AMD-V and that these are activated.

In this way, cost-efficient and scalable VMs can be operated in cloud environments that can be flexibly adapted to the various requirements.

CPU with different cores – what does this mean?

A processor can consist of several cores, which are also referred to as computing units. Processor cores work in parallel, but mostly independently of each other. Therefore, the computing power of a computer generally increases with the number of cores.

• Processors are referred to differently depending on the number of cores: Single-core processors are called single-core, two-core processors are called dual-core and four-core processors are called quad-core. There are also processors with even more cores. The more cores a processor has, the more tasks it can process simultaneously and this significantly increases the overall performance of the system (depending on software performance).
  
• The speed of a processor is specified in Hz (Hertz), MHz (Megahertz) and GHz (Gigahertz). For example, a processor with a clock frequency of 1 gigahertz can execute one billion clock cycles (switching operations) per second. Complex arithmetic operations such as the division of large numbers often require several thousand of these switching operations. Nowadays, processors with several gigahertz are the standard, as this enables very high computing power.
  
• The best-known processor manufacturers include Intel and AMD. If you want to install a new processor, you should make sure that it is compatible with the mainboard. AMD and Intel processors differ in terms of their design, especially in the arrangement of the contact pins for the connection to the socket.
  
• With AMD CPUs, the contact pins are located directly on the processor, which is plugged into the socket of the mainboard. With Intel, however, the pins are not located on the processor but in the socket of the mainboard. In this case, the processor itself only has contact surfaces.
  

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CPU: Differences according to application

A central processing unit that is installed in a conventional desktop PC is known as a desktop CPU. It is developed for use in classic computers and offers a balanced mix of energy consumption and performance. Many modern desktop processors also have an integrated graphics unit, which is perfectly adequate for everyday standard applications such as the internet, office and multimedia.

Mobile processors are used in laptops or other portable devices. Compared to desktop processors, they are usually more energy-efficient in order to extend battery life and keep heat generation to a minimum. They are similar to desktop CPUs in their basic function, but are not quite as powerful.

Server processors differ significantly from desktop PCs and laptops. They have a significantly higher number of cores and are designed to perform several operations efficiently at the same time. As servers are usually operated around the clock and have to cope with a high workload, these CPUs are specially designed for continuous operation and maximum reliability.

Tips, tricks & important information about the CPU with STACKIT

• Ensure efficient CPU resource utilization to optimize costs and energy consumption. Smooth out peak loads, for example through data compression or by shifting non-urgent tasks to quieter times.
  
• Pay attention to transistor density: Inside a modern CPU, billions of tiny electronic switches are at work, ensuring that the processor can deliver enormous computing power. The chip is therefore the heart of your computer.
  
• Pay attention to the CPU architecture, as this determines how the CPU is structured – for example, how many cores it has or which technologies (e.g. virtualization or special instruction sets) are supported.
  
• Registers are particularly fast memory locations directly in the processor. They store instructions and data for a short period of time and thus significantly speed up processing.
  
• Use the appropriate tools, as these offer you valuable help when monitoring and adapting the CPU, for example when setting energy-saving options.
  

Core component for performance and control: the CPU

A CPU consists of several components and is the performance-determining heart of every computer architecture. It processes all commands and data, controls system processes and ensures that programs and the operating system are executed efficiently. The architecture, clock frequency and number of cores significantly determine the performance of a computer. Thanks to advanced technologies and multiple cores, modern CPUs – such as those from AMD-Ryzen or Intel – enable high computing power and flexible adaptation to different requirements – from desktop PCs to mobile devices and powerful servers.

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FAQ – frequently asked questions about CPUs

Why is CPU performance important?

CPU performance is crucial because it determines how efficiently and quickly a computer can process data and perform tasks. A powerful processor ensures that programs start faster, complex operations are carried out quickly and several applications can run simultaneously without delay. A powerful processor also ensures that the computer can keep up with the latest software updates.

How does memory work with the CPU?

The memory in the CPU works on several levels, with the registers being the most important and fastest memory level. As tiny, extremely fast memory areas, the registers store data, instructions and memory addresses that are currently required and provide the processor with very fast access to this information. In addition to the registers, there is the cache memory, which serves as a buffer between the fast registers and the slower main memory (RAM). The cache is larger than registers, but still very fast and serves as a kind of short-term memory for important data and instructions.

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