Exactly How to Choose a CPU: Complete Guide

written by jacob tuwiner Jacob Tuwiner

Here’s the deal:

There is no such thing as the best CPU, only the best CPU for you.

That’s why it’s incredibly important to know exactly what you want to do with your PC before you buy - it’ll help you tremendously when it comes time to pick your components.

In this article, we’re going to talk about the CPU in specific, as it’s imperative that you select the proper brain for your computer.

Without further adieu, let’s talk about how to choose a CPU for your PC:

What is a CPU?

According to Digital Trends:

Short for Central Processing Unit, it’s the chip that executes instructions and moves data around in every major device you own, from the smallest tablet to the mightiest of desktop computers. Whether you’re having trouble with your CPU or want to increase your knowledge, here’s everything you need to know about the CPU, the heart of almost every system.

How to Get the Best CPU for Your Money

Don’t waste your money on the best CPU around if you don’t need it, and don’t skimp on your CPU only to regret it later.

It’s important to get the best bang for your buck, and that means nailing down what you want to accomplish and buying your CPU accordingly.

The best CPU for the GTX 1080 Ti isn’t necessarily going to be the best CPU for the GTX 1070 or the 1060 - remember that.

Once you know what the aim of your build is, you can begin qualifying CPUs. But that doesn’t mean go for the CPU with the highest clock speed, either. Instead, consider how many instructions per clock it can perform (this is going to have a much more significant impact on performance than clock speed alone.)

You should also consider other important information about your CPU like power consumption, heat output, security features, max memory, expected overclocking limits, and more.

Once you’ve got all of that information, you’re ready to make a levelheaded decision about what gives you the best value for your money.

Here are some of the things you should consider:

What Will You Use Your CPU For?

Let’s start out by discussing some common uses. Knowing what you’ll be doing with your CPU is the first step to take before deciding how powerful it should be, and ultimately which CPU you’ll pick for your build.

Using a CPU for surfing the web won’t require nearly as much power as a CPU for an RTX 2080 Ti, for example.

Basic Tasks: $50-$100 range

surfing-web

If you’re building your PC for at home use and won’t be doing any intensive tasks (no, checking Facebook ten times a day isn’t intensive) you can get away with a cheap CPU in the Ryzen 3 or Intel i3 family.

In fact, you may even be able to get away with an even cheaper CPU like the Intel Pentium G4560, but to be completely honest with you, the R3 and i3 families are such a good deal, there’s no reason to get anything less in my opinion.

Gaming: $150-$250 range

gaming pc setup

If you’re using your processor for gaming, chances are it won’t need to be insanely powerful or expensive, and shouldn’t eat up a significant portion of your budget. That’s because most well-optimized PC games primarily utilize the power of your graphics card, which is responsible for 3D rendering and gaming related tasks.

As long as your CPU is a good pair for your graphics card, you won’t have an issue running most games. But if your CPU bottlenecks your graphics card, you’re going to run into some problems.

For example, you wouldn’t want to pair a Pentium CPU with a new RTX 2060.

That’s why it’s important to use the right CPU/GPU combo depending on the types of games you want to play and how demanding the games will be.

However, not all games rely primarily on the GPU - some may use more of the GPU than you may think.

For example, games like ARMA III are far more CPU intensive than better optimized games like Fortnite, which have better PC development teams and primarily harness the CPU.

Still, generally speaking, the CPU is less important than the GPU for gaming. If gaming is all you want to do, there’s no need to shell out $300 for a top-of-the-line CPU like the Intel Core i9-9900K.

For most gaming builds, a mid-range i5 or better yet, Ryzen 5 is a terrific choice.

Creative Media Work & Streaming: $250-$350 range

streaming pc setup

This is where things get a bit more complicated. If you’re building a dedicated streaming PC, there’s no need to get an insanely powerful CPU. Assuming you have a dedicated gaming PC and another PC dedicated entirely to streaming, an i3 or Ryzen 3 CPU will get the job done just fine. If you really want to play it safe, upgrading to an i5 or Ryzen 5 is a good idea.

On the other hand, if you’re going to be streaming from the same PC you’re using to game, a significantly more powerful CPU is necessary.

This is because you have to encode your stream (compressing large video files for easier uploading to the internet). Unlike gaming, encoding places a heavy burden on the CPU.

If gaming puts your CPU under moderate load, gaming and streaming will probably max it out, causing a dreaded CPU bottleneck. It’ll have a negative impact on your gaming experience, not to mention the quality of your stream.

That’s why I recommend using a dedicated streaming PC in addition to your gaming PC if you’re serious about streaming (don’t worry, it’s nowhere near as expensive as a gaming or workstation build.)

However, if you are going to use the same CPU for gaming and streaming, go for a powerful CPU like the Ryzen 7 3700X or the Intel Core i7 9700K. Those top shelf CPUs will give you the best gaming and streaming experience.

What’s the bottom line here?

Streaming uses far more CPU power than gaming alone, so you’ll need a beefier CPU if you’re going to be using the same PC for both gaming and streaming.

Editing and Heavy Workstation Tasks: $400+ range

video editing

Editing video and even photos is one of the most CPU intensive tasks you’ll perform with your PC. That being said, if you plan on doing anything beyond beginner edits, the importance of using the right processor cannot be overstated.

When it comes to editing, a CPU with not just a fast clock speed but also several cores and threads is necessary. That’s why Ryzen CPUs excel in the realm of video editing. They’re known for their powerful cores and threads, and exceed in both single and multi-threaded performance.

Using a six core Ryzen 5 1600 AF is going to be a good CPU for editing. It’s a bit older, but the AF version boasts practically the same performance as the second generation Ryzen 5 2600 for a significantly lower price.

It has six cores and 12 threads, and will handle 1080p and 1440p editing with ease. If you want to step it up a notch, the Ryzen 5 3600 is a terrific choice. Lastly, if you’re a professional editor and want a heavy duty CPU for intense 4K, 60FPS editing, you can’t go wrong with a top shelf option like the Ryzen 7 3800X or the Intel Core i7 9700K.

These CPUs are workstation beasts that can handle just about anything you throw at them, including 1080p games.

Must-Know CPU Specifications

Here are some must-know CPU specifications:

Core Count

cpu cores

Your CPU (Central Processing Unit) is tasked with computing a ton of stuff at unbelievable speeds, and it recruits the use of different cores to do that.

Think of each core like a miniature processor, capable of handling its own computation.

For example, if a single core processor had to computate 5 x 4 x 3 x 2, here’s how it would handle the problem:

  • 5 x 4 = 20
  • 3 x 2 = 6
  • 20 x 6 = 120

Conversely, a multi-core CPU would compute several calculations at once. One core would compute 5 x 4 while the other computes 3 x 2, getting the answers at the same time and multiplying them together at the end, effectively saving time .

That’s why multi-core processors are generally better at handling intensive tasks like video editing, which have a lot of different processes going on at once.

However, most video games don’t fully utilize a ton of CPU cores - in fact, anything more than four cores (maybe six, but that’s a stretch) won’t be used by most modern PC games. Having more than four cores isn’t a bad thing though, especially if you plan on doing literally anything else besides gaming with your PC.

What’s the bottom line here?

The more cores your processor has, the more tasks it can handle at the same time, thus making it more powerful and effective. Generally speaking, the more cores the better. If you plan on gaming and doing any workstation tasks, Intel i5 and Ryzen 5 CPUs with six cores are a great place to look.

Cache Size

CPU pins

Your CPU cache is vital to the speed we’ve all grown accustomed to from modern computing.

Most people think of hard drives, SSDs, and even RAM when they hear “system memory”. But your CPU cache is the form of memory that’s often overlooked and is crucial to your system’s performance.

Your CPU’s cache is a specialized type of memory that’s built directly into your CPU.

But why does your CPU need its own memory when you have RAM?

Well, your RAM is leaps and bounds faster than, say, your hard drive. But your CPU wants data even faster than your RAM can even provide it.

Furthermore, as CPUs continue to increase in power at an incredible speed (Moore’s Law) they’re outpacing RAM modules by wider margins. Without faster memory, your CPU will be sitting around doing nothing as it waits for RAM.

Enter your CPU cache. Unlike system memory which uses dynamic RAM (DRAM) your system cache uses static RAM (SRAM). It’s more expensive and takes up more space but it is significantly faster than DRAM because it doesn’t need to be constantly refreshed in order to hold data.

The average CPU will have a few MB of cache available but it makes a tremendous use out of it. When a CPU accesses something from the main system RAM, it generally stores it in its cache, then using advanced algorithms to guess the next set of instructions it’ll need next, and will fetch that data from the RAM as well.

Basically, your CPU will ask the RAM for any data it thinks it will need, and stores all of the data in its cache for immediate use.

ram cache cpu diagram chart

Since these guesses aren’t perfect, sometimes the CPU will have a “cache miss” where it tries to find the data it needs in its cache but can’t and instead requests the data directly from the RAM, which slows things down.

Moral of the story? More cache is better and you’ll typically find higher end processors with a larger cache.

Socket Compatibility

cpu socket

Unlike many PCI Express sockets which can cater to a bunch of different components, nearly every new family of CPUs has its own socket.

What does this mean for you?

You’ll have to pay a bit more attention to your motherboard’s socket type than you do to the electric socket on your wall which is compatible with every plug in your house.

Intel and AMD sockets are definitely the most noticeably different. Intel makes use of a mounting system called “Land Grid Array” (better known as LGA). All this means is the CPU itself has tiny electric contact pads, while the pins themselves are in the socket on the motherboard.

When you’re buying an Intel CPU, you’ll probably notice a lot of them are called “LGA 1151” or “LGA 2011”. The number corresponds to the number of pins are on the bottom of the socket and pads on the bottom of the CPU.

Why do CPUs need thousands of little pins? Power delivery!

CPUs can consume a lot of power and dividing the power draw between many different pins helps to stabilize power delivery.

On the other hand, AMD CPUs use something called Pin Grid Array (PGA). Unlike Intel, AMD CPUs themselves have the pins, and AMD motherboard sockets have the little holes for inserting the pins. AMD also doesn’t use the same naming system as Intel, which means you shouldn’t correlate the numbers in socket types with the actual number of pins on the chip.

Integrated Graphics Processing Units

integrated graphics chip

Some CPUs come with integrated graphics, meaning you don’t need to buy a dedicated video card to send output to your monitor. Assuming your motherboard supports it, you can plug an HDMI cable directly into your motherboard and see life on your monitor.

New chips like the Ryzen 3 3200G (APUs) have become incredibly powerful even in light gaming situations. For those of you who plan to use your PC for surfing the web and other tasks that won’t tax your graphics processor, using a CPU with integrated graphics is definitely a viable option.

However, if you’re planning on doing any 3D rendering (yes, that means gaming) I highly recommend investing in a dedicated GPU. No matter how good your CPU is, integrated graphics will never compete with the sheer power of a dedicated graphics card, especially when it comes to gaming.

Core Clock Frequency

core clock speed

Most manufacturers like to tout their CPUs clock speeds, not to mention the thriving community of insane overclockers that push their rigs to the max just to squeeze every last drop of performance out of their chips.

That said, it’s safe to say if you’ve only heard of one of the CPU specs we’re talking about now, it’s CPU clock speed.

We’re going to touch on why it’s not actually incredibly important in our section about CPU buying tips, but let’s first discuss what CPU clock speed is.

Speed in MHz or GHz measures how many clock cycles a CPU goes through each second, and a clock cycle is when an electrical pulse hits your CPU, allowing it to execute instructions and keep your CPU in sync with the rest of your computer.

The higher your clock speed, the more cycles it can handle at a time. But I’d warn against using clock speed as your primary buying factor. In addition, don’t use it as a metric to compare the power of two different CPUs unless they’re both of the same microarchitecture and have the same number of cores.

Core Clock Doesn’t Matter as Much as You Think

clock cycle image

It seems like a higher clock speed is always better (and usually it is) but it’s not the end all be all specification you should care about, as a higher clock speed doesn’t necessarily mean a faster CPU. There are a bunch of other factors to consider that determine the speed of your CPU.

Instead of simply measuring how many clock cycles per second a CPU can handle, it’s better to consider what’s actually going on behind the scenes during each cycle.

It’s important to determine how much data is actually being processed during each cycle - modern processors are able to process several different things simultaneously via a process called pipelining.

Much like a factory divides assembly into different stages, CPUs can split data into different sections and process them accordingly. It makes production (and in this case computing) significantly faster.

CPU pipelining is far more complex than a factory assembly line, but exactly how the CPU manages different tasks at once is heavily dependent on the chip’s microarchitecture.

Because the number of instructions per clock cycle and the pipelining efficiency can vary tremendously between brands and models, clock speed can be quite deceiving.

And like we mentioned above, CPUs need to read ahead to predict what data they’ll need to access from their cache next. Especially considering how many different user inputs they must process at the same time, this task is insanely difficult.

Think about what the CPU is doing when it’s processing bullets flying at you after a grenade explodes in a demanding shooter video game.

csgo gameplay

High-end CPUs need to do a better job of predicting what kind of processes are coming next without interrupting the function of other components on your computer. This is known as branch prediction, and CPUs with better branch prediction will have superior performance, and you won’t be able to tell purely based on the CPU’s clock speed.

Lastly, if you’re performing CPU intensive tasks that require a boat load of data processing like video editing or encoding, having more cores to spread the workload will usually render better performance than higher clock speeds alone.

As you can see, there are a plethora of other factors that contribute to your processor’s performance besides clock speed which you need to take into account.

Now, clock speed shouldn’t be ignored completely, it’s still a solid number to take into consideration. But it’s really only a good metric to compare against another CPU if they’re both of the same microarchitecture and number of cores.

The point is just that it shouldn’t be a tremendous factor in your buying decision.

Boost Clock Frequency

boost clock frequency

Boost clock frequency is pretty simple once you understand the base clock - it’s kind of like your processor kicking itself into hyperdrive when it needs a bit of extra processing power.

Let’s say your CPU has a core clock of 3.5 GHz and a boost clock of 4.2 GHz. The base clock is its normal operating frequency, but if you start rendering a video while editing in Photoshop, your CPU will need to kick it up a notch and will start running at 4.2 GHz on its own, drawing more power in the process.

Unlike overclocking which we’ll touch on below, you don’t need to do anything to increase the core clock of your CPU to its boost clock.

When I’m considering a new CPU, I’ll look at its boost clock to determine the CPU’s maximum “out of the box” performance.

Threads

This is the total number of independent processes a CPU can take on at the same time. In theory, this number should be the same as the number of cores the CPU has.

But many processors have multithreading technology that helps them operate faster. Hyperthreading (Intel) and Simultaneous Multithreading (AMD) are effectively the same thing, but each company has their own name.

Multithreading capabilities help one core create two threads. This effectively doubles the amount of work that a single core can handle at one time. More threads means better multitasking functionality.

A CPU with four cores and multithreading has four physical cores and four theoretical cores, meaning it (kind of) has eight cores total, not four.

But don’t be fooled - physical cores are better than just threads any day.

Overclocking

overclocking cpu

As you know now, your CPU’s core clock frequency is a measure of the number clock cycles your CPU can handle every second. The more clock cycles, the faster it can execute instructions.

When you “overclock” your CPU (or any other component in your PC for that matter) you’re essentially sending more power to increase its operating frequency. The more electrical pulses you send to your CPU each second, the faster your CPU will be.

Overclocking is the best way to squeeze every last drop of performance out of your rig, and has become increasingly popular over the years, largely because of how easy it is. For most people, it’s a no brainer.

Some CPUs are better suited for overclocking than others. AMD CPUs, for example, are well known for their overclockability, especially their most recent Ryzen lineup. Intel CPUs are also overclockable, but only if they’re designated with a “K” at the end of their name.

Some Intel CPUs are locked from the factory, meaning they can’t be overclocked, whereas their “K” models are unlocked and you can push them to the max. Conversely, AMD CPUs are all unlocked and can be overclocked with an aftermarket cooler easily.

overclocking cpu picture

However, increased performance comes at a cost, particularly with temperatures and the longevity of your chip. More electricity pumping through your CPU means higher temperatures and, if you mess things up, the potential to overheat your CPU and potentially cause damage.

If you do decide to overclock, using an adequate CPU cooler is required, and that usually means going with an aftermarket option. You don’t need to go all out on an insanely expensive water cooler.

Instead, a simple aftermarket cooler like the popular Hyper 212 Evo from Cooler Master is a great choice for most beginner builders that want to squeeze some extra performance out of their chips.

I mentioned overclocking can damage your CPU - while that is the case, it’s unlikely, especially considering how easy overclocking has become. Assuming you’re using an aftermarket CPU cooler and have a motherboard BIOS that makes it easy, overclocking is a breeze. Follow just about any YouTube tutorial for your chip and you’ll be just fine.

We also have an awesome guide on overclocking your CPU which you can check out by clicking that link. It’ll walk you through overclocking step-by-step so you don’t have to worry about doing something wrong.

Thermal Design Power

cpu temps

Thermal Design Power (also known as TDP) is a measure of the amount that processor will output in a realistic but heavy use scenario.

But TDP is a bit trickier than that, since it’s measured in watts. Most CPUs range from 65 watts to 95 watts TDP, but contrary to popular belief, TDP is not a measure of direct power consumption.

Yes, a watt is a unit of measure for electrical power over time, so that can refer to electrical power being consumed, or the thermal power being output (both uses are correct).

And although it’s not a measure of the exact amount of electricity your CPU (or another component) is using, it’s tightly related.

Still, it’s a loosely thrown around number, as manufacturers will often assign a single TDP to an entire family of chips, despite some chips being far more powerful (and using more electricity).

In addition, some manufacturers estimate TDP based on an extreme use case scenario, like doing heavy editing for hours on end, while others rate TDP based on what you’ll see in the real world.

What does this mean for you? Why should you care about TDP if it’s not an actual measure of electrical consumption?

TDP is a great way to decide what kind of cooler you’ll need for your CPU because it’s a measure of estimated heat output, especially if you plan on overclocking.

Processors need to be kept below their maximum operating temperature, at which point they’ll turn themselves off completely, or throttle their performance to protect against overheating.

What do You Need More: Clock Speed, Cores or Threads?

Again, the answer to this question depends on your specific use case scenario. For example, higher clock speeds mean faster responsiveness and better single threaded tasks (audio editing and other old applications).

On the other hand, most modern tasks use lots of cores and threads at the same time, like high resolution video editing and gaming. If you’re doing professional video editing, go for as many cores as possible.

But for most computer users (gamers included) a CPU with four to eight cores and a clock speed of at least 3.0 GHz should do fine.

AMD vs Intel

amd vs intel

If you’re reading this article you’re probably new to PC building and haven’t joined in on the eternal war between Team Red and Team Blue.

Here’s the deal:

Some people will stand by Intel no matter what, and same with AMD. But the fact of the matter is you shouldn’t choose your CPU based on which brand you prefer, but rather which CPU will give you the most bang for your PC gaming buck.

Both Intel and AMD have their strengths and weaknesses. There is no best CPU, there is only a best CPU for you. Intel is a reliable company that has been known for creating top-tier CPUs for years now. In fact, they were often regarded as the “premium” company that people with higher budgets would turn to for additional performance.

AMD, on the other hand, was known for overpromising and underperforming. Their CPUs usually flopped on performance, including their FX series that had high core counts but not much else to offer in terms of performance, and fell short of Intel time after time.

Most would recommend AMD only for those on a tight budget.

But when AMD first came out with their Ryzen line of CPUs back in 2016, they took the market by storm. Not only did they deliver on their promises, they over delivered and knocked Intel on its butt.

For the first time AMD CPUs were not just cheaper than Intel’s closest offerings, they also usually outperformed Intel in nearly all tests, including gaming.

That holds true today - if you’re thinking about buying a new CPU, I’ll almost always recommend a Ryzen chip over an Intel chip as they tend to have the best bang for your PC building buck.

But again, there is no “best” CPU, there is only the best CPU for you. Hopefully these CPU buying tips helped you out enough to make an informed decision.