Undertaking the task of building your own PC can be overwhelming. You need a variety of components and you need all your components to work together. One of the most important PC components is the Central Processing Unit, or CPU. Your choice of CPU will determine what kind of functionality you can expect from your PC, so it’s important to think about how you’re planning to use the PC. Is it a media centre, a gaming rig, or a video editor? Are you building a PC for your home office, or is fun the ultimate goal? And before you go shopping, familiarize yourself with the technical specifications of CPUs so you can make an informed choice.

CPUs: The brains of the operation


Your PC’s central processing unit (CPU) is the brain of your computer. It does all the heavy thinking for every task, and coordinates the tasks being handled by the other components in the computer. Your CPU needs to have enough power, enough multitasking capacity, and enough data transmission capacity for the jobs you ask of it.

CPU compatibility

Your CPU is designed for a specific type of connection to the motherboard called the CPU socket. And if the CPU you buy is incompatible with your motherboard, your building process grinds to a halt. The different CPU manufacturer’s each have their own socket standard. And on top of that, the socket design is updated and modified with new iterations of the CPU chip. So, your 13th generation CPU won’t fit a 12th generation socket. To save yourself the headache, make sure to check the CPU maker’s website for the socket requirements before you buy.

CPU technical specifications

It can be confusing to sort through the various CPU statistics in hopes of finding the ones that impact your PC build. So, here’s a quick overview of the primary specifications of a CPU and what they mean.

CPU lanes

Your CPU will have dedicated connections available for some of the peripheral component interconnect express (PCIe) slots on your motherboard. These connections are the CPU lanes, and there are a finite number of them that can be assigned. Your video card will take most of them up. If you decide to go wild with additional PCIe components, you may exceed the lanes available and lose some functionality. So keep the number of lanes in mind when you add components.

CPU cores

Your computer takes a big computational task and breaks it into multiple smaller sub-tasks. When all of the sub-tasks are done, your big task is finished. Your CPU cores are physical components on the CPU itself, and each of them can work on an individual task. So more cores means more simultaneous computational tasks being done. And that means faster overall processing. The number of cores can range from 2 to 24. If you’re watching Netflix, 2 cores is perfectly adequate. But if you’re running several programs concurrently, or running applications that need a lot of processing power, you’ll benefit from more cores. 8 cores CPUs are currently the most common, but 16 core CPUs are gaining ground. You can expect 24 cores to become dominant in the next few years.

Clock speed

The clock speed Is the most direct measurement of your CPU’s raw speed. It measures the number of times per second your CPU cycles, and the more cycles per second your chip can do, the faster it goes. It’s not the only defining factor in terms of speed, but it is one of the most important ones. Some CPUs have the capacity to run the chip at even higher clock speeds (overclocking), If that sounds intriguing to you, make sure you read up on what it entails and the possible drawbacks. Overclocking is not for the casual PC builder.


Unlike the CPU cores, threads are not physical parts of CPUs. They are virtual components that manage a related pile of tasks that the cores are working on. Your threads make sure that the related tasks have the resources they need and are ready in time for dependent tasks to use them. The threads pass the tasks to the CPU cores.


Your CPU’s cache is memory that is dedicated for the CPU’s exclusive use. Since it is physically connected to the CPU, the cache is faster to access than the main system memory. More cache means less time spent waiting for data from the main memory. There are usually two caches: L1 and L2. You’ll be looking at the L2 cache when shopping for a CPU.


This is a number that doesn’t mean much until it means everything, and you have a catastrophic hardware failure. Okay, I’m being a little overdramatic. Most PC users won’t have their CPU get hot enough to burst into flame under regular conditions. But as you push the performance of your CPU, it will heat up. Overclocking your CPU to get an advantage against your gaming opponent will increase the heat of the chip. And if you add in the heat coming from the other PC components, you can face heat issues. Make sure you have a cooling solution that will keep your CPU at an optimal operating temperature.


You have two CPU designers to choose from: AMD and Intel. Each generation of CPU sees these two companies competing to have the best CPUs on the market. Right now, AMD seems to have a slight edge, but everything could change in six months. The good news for you is that either is a great choice for your PC build. It’s really a matter of the technical details of the chips, not the company that designed it.

The right CPU for the right build

Your CPU choice is shaped by the overall purpose of the PC. Here are a couple of scenarios for your consideration.

Media centre PC

You want a new computer to serve as the media hub for your living room. Raw power won’t be a requirement, and neither will speed. You would be better served to pick an affordable CPU and save some money.

Home office PC

Your line of work is the important variable in this situation. If you’re only writing emails and documents, a high-powered CPU won’t have much of an effect. On the other hand, if you’re doing graphic design or multimedia creation and editing, you’ll want a CPU that can handle the heavy workload. But generally, you can select a CPU that balances power and affordability.

Gaming PC

This is the scenario that demands all the CPU power you can throw at it. Your CPU is going to run hot, especially if you decide to overclock, so take the temperature rating as a guiding principle in your build. Your gaming CPU will be the crowning jewel of the system (okay maybe it will be tied with your video card for most impressive component). Every part of your gaming PC build will be chosen to optimize the speed, power and communication of the CPU to the rest of the system.

CPU Checklist

A good component shopping trip depends on getting the right part that will work with the rest of your PC. This is a basic list of the parts that your new CPU has to be compatible with.

  • Motherboard socket
  • CPU cooler
  • Motherboard chipset
  • PC cooling accessories (Do you need more thermal paste?)

Next steps 

If you want to learn more about other PC components, make sure to check out our series on how to build your own PC. You can find all the PC components you would need, including CPUs, at Best Buy. To learn more about building your own PC and PC components, be sure to check out all the posts in this series.

Chris Loblaw
Chris is a novelist, avid gamer, tech enthusiast, and proud dad of a 13-year-old video game master.


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