August 08, 2022
How to Choose a CPU
This comprehensive guide will cover everything you need to know to choose the best CPU and make sure it is compatible with your PC.
What is a CPU?
A central processing unit, or CPU (also called a processor or central processor), is electronic circuitry that allows for all the other PC components to function. The CPU interprets binary signals and executes the instructions given to it from programs, your operating system, and other PC components, performing calculations, making logical decisions and completing input/output operations.
Instead of taking in punch cards with vacuum tubes like the olden days of computing, CPUs today have billions of transistors that allow modern devices such as laptops, tablets and smart devices to function.
What CPU Specs You Should Care About
You can think of cores as individual processors. Each extra core adds significant performance to the CPU and an increased ability to multitask seamlessly. Having more cores helps the processor multitask because each core can be focused on a specific task. CPUs with numerous cores have become the new norm as modern software and games begin utilizing multiple core CPU technology to increase performance drastically.
Most CPUs you’ll find today have between two and 64 cores, with anything beyond 32 cores being useful to only the most advanced use cases, including AAA gamers who are also streaming, 3D video rendering and editing, and other demanding tasks. At least four cores are highly recommended for modern users, and six to eight cores should be enough for most users outside advanced use cases.
Many programs can’t utilize all the cores and it will not make a difference in your system’s performance to increase cores further. Be sure to check on the software you want to run and the optimal number of cores for it.
If cores are the individual processors in the CPU, then threads are the number of tasks that those cores can perform at any one time. This is important to know because modern CPUs will often have more threads than cores. This means that each core can perform more than one task at a time. Adding threads is not as powerful as adding cores but does increase the CPU's overall performance.
Multithreading or hyperthreading allows for a core to perform two lines of execution simultaneously, which the operating system interprets as two logical cores. When comparing two CPUs with the same number of cores, the CPU with more threads offers greater power, although the additional threads do share the same resources.
Measured in gigahertz (GHz) in modern CPUs, the clock speed is the rate at which the processor operates. For example, a clock speed of 3.0 GHz means the CPU can handle up to three billion cycles a second, or instructions the CPU can execute within a single clock cycle, or the time between the opening and closing of the billions of transistors within the CPU.
Typically, the faster the CPU runs, the better it performs, but that is not always the case. Factors previously mentioned, such as core and thread count, can also significantly impact performance. When determining CPU power, it is essential to consider all three of these specs. A slower CPU with more threads or cores could easily outperform a high-speed processor with less threads or cores.
Max Clock Speed – Should You Overclock?
You’ve probably noticed CPUs and computer specs often include max clock speed. Some users, particularly gamers, choose to overclock their CPUs, meaning they crank up the clock speed higher than the manufacturers intend.
Note that not all CPUs can be overclocked and not all motherboards allow for overclocking. All AMD CPUs can be overclocked but only Intel CPUs ending in “k” can be overclocked. If you choose to do this, make sure you have a cooling solution in place to account for the additional heat that will build up in your case from overclocking.
TDP (Thermal Design Power)
The TDP of a processor is how much heat it’ll give off and the amount of power a processor needs to function optimally. This number is important because it lets you know just how much cooling you are going to need for that CPU as well as what wattage of power supply your computer may need (in addition to knowing the TDP and power draw of your other PC components). Some processors come with cooling options that can help save money on your overall budget.
There are many options when choosing how to cool your CPU, so make sure you know exactly how cool your processor needs to be. Overheating a processor can result in catastrophic PC failure and cost you unnecessary time and money.
A CPU's cache functions like that of a computer's memory or RAM. The cache is a small, segmented section of memory that stores temporary files, and this data can be accessed extremely quickly. Processors with a larger cache size can store more data for rapid retrieval and processing. It mostly comes in handy for multitasking
Like all tech, CPUs are constantly releasing new versions and upgrades. New generations often showcase cutting edge technology that can have a drastic effect on performance. Sometimes, expensive new features may not be needed for your build — so purchasing an older generation could save you money. Keep in mind that as new generations come out, so does new software that utilizes that generation's technology, which may be needed to run programs optimally.
Nothing is more frustrating than going through all the steps to choose a CPU just to find out that it doesn’t fit in your build or is incompatible with your motherboard. The enclosure on a motherboard that holds a CPU is called a socket. They come in many different shapes and sizes, so it is essential to know what type of socket your CPU uses and what’s compatible with your motherboard.
For example, various CPU manufacturers can require different sockets, making them compatible only with specific motherboards. For instance, AMD CPUs use the same AM4 platform for every consumer CPU and APU they offer. Some motherboards may need a BIOS update to be compatible with AMD Ryzen CPUs.
Integrated Graphics Processing Units (GPUs)/Accelerated Processing Units (APU)
Some computers have their GPUs integrated into their CPUs on a single die. In these computers, the GPU shares system memory for graphics and video with the CPU. Combining the CPU and GPU uses less power and generates less heat, increasing device battery life. They also cost less than a separate, also known as discrete, CPU and GPU. The graphic performance of devices with integrated GPUs is often less than a device with a discrete CPU and GPU, but not always. You’ll most commonly find integrated GPUs in small form factor devices like laptops, tablets and smartphones.
AMD coined accelerated processing unit (APU) in 2011. APUs contain the GPU and CPU on a single die, much like integrated GPUs, and serve a similar role. APUs are performative chips used in modern gaming consoles and some budget friendly gaming laptops. Some APUs can even outperform budget discrete GPUs and with lower power consumption.
What Do You Want to Do with Your CPU?
Knowing how you will be using your PC is crucial in choosing the best CPU for you. Knowing just how much power you need can help balance your budget to other areas of your build.
The first step in building any computer is to determine what that PC's primary use will be. Knowing your needs will allow you to prioritize where to spend when purchasing your CPU. If you’ll only be using your machine for basic office work or browsing the web, for instance, you can save some money on your CPU because you will not necessarily need high performance.
Other tasks, however, require a more powerful processor, such as 3D rendering and 4K video editing. Some devices such as servers, desktops or mobile devices may also require specific processors to perform their best. Here are a few specific use cases for CPUs and what we recommend for each.
If you’re mostly using your computer for browsing the web, word processing, and checking your email or social media, you don’t need anything beyond a basic CPU.
For AMD, a Ryzen 3 processor should be more than up to task. In fact, you could probably save some cash and purchase a laptop with an APU or Athlon series, or A-Series CPU.
For Intel, the equivalent would be an Intel i3 processor on the high end of home user needs. To save, you could investigate PCs with integrated GPUs, or the Intel Celeron or Pentium Gold, Silver or Xeon series.
A CPU with a clock speed over 2.0 GHz is most likely overkill for this use case.
Small Business & Enterprise
What kind of CPU needed for small business users depend on the role of the individual user. Someone who is a copywriter or social media manager wouldn’t need as powerful of a PC as the web designer or video editor. If users are mostly using word processors and basic spreadsheets or presentations, an Intel i3 or AMD Ryzen 3 should be more than enough to get the job done, and you may be able to get away with the same CPUs as home users.
For users in design or creative editing roles, or number-crunching large databases, you should consider an i5 or Ryzen 5 CPU, and possibly an i7 or Ryzen 7 for 3D rendering/modeling, video editing, or simply future-proofing your systems.
If you want to get a more precise idea of what CPU your individual team members need, check out the specifications of the software they’ll plan on using to learn how many cores are needed to run the software optimally. Clock speed also comes into play—for instance, Adobe Photoshop and Lightroom require a 64-bit CPU with a clock speed of at least 2.0 GHz.
For most AAA titles like Elden Ring or Resident Evil 3, an AMD Ryzen 5 or Intel i5 processor is about the baseline for smooth gameplay and preventing the dreaded lag. If you’re looking to also stream on the same PC, you’ll need a stronger CPU.
However, for most gamers, you’re best off getting the required CPU for whatever title(s) you’re looking to run as well as minimum cores/clock speed and focusing on purchasing a powerful GPU. Particularly for streamers, at this level you should consider a CPU cooling solution beyond a simple fan.
Types of CPUs
There are several types of CPUs out there. Knowing your budget and workload are key in determining what type of processor is best for you. Narrow down your choices first by determining which type of CPU you need.
Designed with mobile devices and laptops in mind, these CPUs tend to be slower than their desktop or server counterparts. On the other hand, they are generally more compact so they can fit within these devices.
Rigorously tested and built to run 24/7, server processers are the powerhouses of the CPU world. These components are tested in high-temperature and high-stress simulations to ensure that no matter what, your server can keep running optimally. Server processors are ideal for hosting multiple applications, maintaining regular backups or processing mass amounts of data. These processors are by far the most powerful option, but they come at a much higher cost.
Like other CPUs, a desktop processor's job is to process data, but with a desktop user in mind. These processors are not designed to run a heavy workload non-stop but instead focus on other user needs. Desktop CPUs are more affordable than their server counterparts and can excel at tasks like gaming or internet browsing. These processors can also be used for overclocking, allowing users to push their components to the utmost limit. There are many different desktop CPUs out there, so it's important to know what specifications to pay attention to when shopping.
How to Choose Your CPU
Now you know everything you need to to choose the best CPU for your machine. Here’s a quick summary to help you decide:
- Determine PC Workload. After determining your PC's expected workload, you’ll know just how powerful your CPU will need to be.
- Budget. You can balance your budget for your CPU, being careful not to overspend or purchase a processor that is unable to meet your needs.
- Review Specs. By paying attention to vital specifications like core and thread count, clock speed, and more, you can compare your top choices to make your selection.
- Match Motherboard Socket. Before finalizing any purchases, make sure to check that your motherboard has the right socket shape for your CPU.
- Match Motherboard Chipset. Ensure that your motherboard's chipset is compatible with your CPU so you can make full use of all your CPU and motherboard features.
Find the best CPUs on CDW.com
We hope this guide on how to choose a PC has helped you narrow your options down. If you’re ready to shop, explore the CPU selection at CDW now.