A central processing unit (CPU) is the main processor in a computer that executes instructions and runs programs. It handles calculations and routes data between hardware and software. This chip plugs into the motherboard and handles the electronic instructions that make your system operate. All system actions route through the CPU before reaching other hardware.
Basically, the CPU acts as the system’s coordination point by directing data between hardware and software. In more technical terms, the CPU makes simple calculations and then performs a small number of processes based on the results of those calculations.
A CPU includes several internal units that handle instruction flow, memory access, and calculations:
Control unit (CU)
Arithmetic logic unit (ALU)
Address generation unit (AGU)
Memory management unit (MMU)
Cache
Buses
Clock
Registers
Wires
Transistors
Some modern CPUs also include graphics processing units (GPUs).
How does a CPU work?
A CPU processes data through a fetch-decode-execute cycle that reads instructions, interprets them, and sends the results to system hardware. This cycle runs billions of times per second to drive every task on your computer.
For example, when you open a program and begin typing, the CPU receives instructions from the keyboard and program on what to display on the screen. Then, it sends instructions to the graphics card to display text and images on the monitor. If you want to open or save files, the CPU coordinates with the hard drive and random access memory (RAM) to move files where you can use them.
The speed and cache size of your CPU determine how much data your computer can handle at once. Modern CPUs can have billions of transistors on a single chip, allowing the CPU to process instructions so quickly that letters seem to appear on the screen simultaneously while you type.
What is CPU clock speed?
CPU clock speed measures how many cycles per second a processor can complete, expressed in GHz. Higher clock speeds allow the CPU to execute instructions faster, though modern performance depends on more than raw frequency.
Through the 1990s and 2000s, clock speed was one of the most important factors when choosing a processor. That began to change for modern CPUs. Processing more instructions increases heat, causing more wear and tear. So chipmakers focus on other areas to improve CPU performance. This may mean that some older CPU models have a higher clock speed than newer models, though the more recent models still perform far faster.
What is a multicore CPU?
A multicore CPU contains two or more processing units that allow the system to work on multiple tasks at the same time. More cores improve parallel performance for workloads like video editing, rendering, and data processing.
Most laptops and desktops have 2- to 16-core processors, though some desktop computer models have 16 or more cores. Adding more cores to the CPU doesn’t automatically drain the battery faster or create higher loads, but it can add efficiency and speed (and increase the price tag). This is why chipmakers focus on cores as a distinguishing feature rather than clock speed.
A higher number of cores can make a considerable difference for demanding applications, like video editors, gaming, or CAD applications. Some CPUs come with as many as 64 cores. A 64-core processor is overkill for the average business user. However, companies that need high-end processors for video editing or graphic design should also upgrade their RAM (64 GB or more), graphics, and video cards to keep up.
How do you maintain a CPU?
CPU maintenance focuses on preventing overheating and keeping airflow clear. Monitoring background processes, maintaining ventilation, and removing dust help the processor run efficiently.
A computer virus can run unobtrusively, straining your CPU. Cybersecurity best practices can help you safeguard your environment and spot potential incidents before your CPU sustains physical damage.
For peak performance, also ensure there’s good ventilation. Dust can build up on the CPU and its fan, preventing heat from dissipating. Taking the computer apart and cleaning off the dust can improve its performance.
To clean dust from the CPU and improve cooling, follow these steps:
Power down and unplug the machine.
Open the computer.
Spray out the motherboard with compressed air.
Use alcohol wipes to gently remove debris.
For best results, you may need to repeat this process every few months.
How do you choose a CPU for business use?
To choose a CPU for business use, match the processor’s core count, clock speed, and efficiency to your workload and budget.
The good news is that most modern CPUs are well matched for the average business user. That means you can generally choose a laptop or desktop for reasons outside the CPU, like price, hard drive, and compatibility with existing hardware. Most modern CPUs can handle general office tasks like email, web browsing, and document editing without issue. However, businesses with more intensive computing needs should consider the CPU more carefully.
CPU brand and model
Intel and AMD are the most well-known chipmakers, with the Intel Core (and newer Core Ultra) series and the AMD Ryzen (7000 and 8000) series topping the list of popular CPUs. Choosing between them usually comes down to whether you prioritize raw speed or overall value. Historically, Intel chips have offered slightly faster single-core performance, while AMD models often deliver better efficiency and pricing — but the latest generations are now very close in both power and price.
Modern Intel and AMD CPUs come in multiple tiers that range from entry-level to high-performance. Core counts, clock speeds, and efficiency vary widely across generations. As of 2025, most business-class systems include 6 to 16 cores that easily handle everyday workloads, while high-end models go well beyond that for demanding tasks like video rendering or data analysis.
Cores and threads
To choose the right CPU for your business, determine your business needs and work backward. Basic business functions generally require four to eight cores. Many companies overestimate their processing needs, but most users don’t need anything too fancy. An i5 can generally get the job done. CPUs with 16 or more cores can support more advanced business needs, such as processing massive data files, rendering video, and navigating 3D images.
Many processors also offer multithreading options. Threading allows a single CPU to process more than one task at a time. Some processors, like the AMD Ryzen Threadripper series, have multithreading options on every core. Others, like some of the Intel Core series chips, have multithreading capabilities on half of the cores while the rest perform with a single thread.
When you compare CPUs with the same or similar cores, you might look at the multithreading capabilities to choose between the two.
Clock speeds
While clock speeds are no longer the defining characteristic for choosing CPUs, they can still play a role in the speed and power. Many CPU models include two clock speeds: the boosted max speed and the baseline speed.
Most chipmakers advertise the max speeds, but also look closely at the baseline speeds. Basic business users typically need clock speeds ranging from 2.0 to 3.5 GHz. More intensive users often require clock speeds of at least 3.0 GHz.
Cache
CPUs include a small amount of memory storage called cache. This allows the chip to access certain data rapidly when multitasking, speeding up performance. Chips with more available cache support more complex operations and programs. Basic business users usually need around 12 MB of cache on their CPUs. Advanced business users may need 20 MB or more.
Still have CPU questions or want to swap specs with fellow hardware nerds? Join the conversation in the PDQ Discord or swing by the PDQ community to get real-world insights from sysadmins and IT pros who’ve been there, tested that.
