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How to Choose a CPU: Clocks, Cores, and More Explained

Written by Azzief Khaliq
Last updated Apr 1, 2021

Affiliate Disclosure: When you purchase products through our links, we may receive a commission at no additional cost to you.

One of the most essential skills every PC enthusiast should know is how to choose a CPU. Your CPU, along with your motherboard, is the beating heart of your system. The choices you make here will directly affect what your rig will be good and, unfortunately, not so good at.

Sure, you can rely on buying guides, like our own list of the best motherboard and CPU combos. But we firmly believe that everyone should learn to make their own PC hardware decisions. It might seem like an intimidating task if you’re not used to it yet, but that’s why we’re writing this.

Let’s get started.

AMD vs. Intel

AMD Ryzen CPU

Source: AMD

Intel used to rule the roost for gaming performance, but AMD’s Zen 3 CPUs from last year have put them on top. If you’re looking for outright performance, AMD’s 5000-series CPUs—the Ryzen 5 5600X, Ryzen 7 5800X, Ryzen 9 5900X, and Ryzen 9 5950X—are the best right now.

There’s one problem with Zen 3, though: supply. Even though it’s been nearly five months since launch, it’s still almost impossible to find AMD’s 5000-series CPUs at prices anywhere close to AMD’s suggested retail price.

Things seem to be improving slightly, with Ryzen 7 5800X supply (and prices) gradually stabilizing. However, the 5600X and 5900X are still hard to find and are selling significantly above MSRP.

Intel CPU

Source: Intel

If you need a CPU now, you’ll likely be choosing between AMD’s 3000-series CPUs (most of which are still available at MSRP) and Intel’s offerings. Here, Intel has the advantage for gaming. But if you’re ok with lower maximum FPS numbers in exchange for better content creation and productivity performance, AMD is a good pick.

You can’t really go wrong with either company, though, as both make solid CPUs.

Decoding CPU Model Names

When you’re looking at CPU model names, it’s pretty easy to get confused by names like “Ryzen 9 5950X” and “Core i9-10900K”. There’s a logic behind the numbers, no matter how random they may seem. Understanding how to read them can help you quickly identify CPUs that are and aren’t relevant to your needs.

These numbers tell you what generation the CPU is from and how it performs relative to the manufacturer’s other chips. This makes it easier to compare processors, as you’ll be able to tell which are newer and faster just from the names.

Both AMD and Intel follow a similar structure. First up is a name and number that denotes the CPU’s tier within the product stack:

 AMDIntel
Lowest TierRyzen 3Core i3
Ryzen 5Core i5
Ryzen 7Core i7
Highest TierRyzen 9Core i9

After that, the first one or two digits signify the CPU generation. A Ryzen 3 2200G would be a second-generation, lowest-tier AMD Ryzen CPU. A Core i5-10600K is a mid-tier CPU from Intel’s 10th generation. Even when the number doesn’t directly match the CPU generation, like AMD’s 5000-series products, the number helps to show that it’s a newer CPU than parts numbered 2000 or 3000.

Finally, the last three digits represent the CPU’s place within that particular tier and generation. An AMD Ryzen 9 5950X is higher up in the performance ladder than the Ryzen 9 5900X, and the same goes for an Intel Core i5-10600 vs. a Core i5-10400.

There are also a few suffixes you should pay attention to on Intel CPUs, most notably the “K” suffix. This means that the CPU can be overclocked. “F” is also worth paying attention to, as it tells you that the Intel CPU in question doesn’t have integrated graphics.

Both Intel and AMD also make budget CPUs below their Core and Ryzen brands. Intel’s most budget-oriented CPUs are branded Celeron or Pentium, while AMD has their Athlon CPUs at the low end. The names differ, but the same rules still apply. Higher numbers denote newer architectures and faster components.

Budget

Let’s face it: most of us can’t afford to spend willy-nilly on computer parts. So the first order of business when picking a CPU is determining how much you should spend on it. Skimp on a CPU, and it might hold back your other components, like the graphics card. On the other hand, overspending on a too-powerful CPU will leave a lot of performance on the table when your other parts can’t keep up.

This is quite a personal choice, but here are some rough price ranges that we think you should stick to after budgeting for your other components:

  • Everyday tasks (web browsing, online video, casual games): less than $100
  • Mainstream gaming: $200 – $300
  • Streaming and content creation: $300 – $500
  • High-end creative work: $700 and up

We’ll have some concrete CPU recommendations at the end of this article, but these are good numbers to have in mind while you’re reading through. If you’re still trying to determine how much you should spend on your gaming rig overall, check out our article on how much a gaming PC costs.

Motherboard Compatibility

Before we get into the specs and technical aspects of what to look for in a CPU, it’s absolutely critical to ensure that whatever processor you’re getting is compatible with your motherboard. Firstly, be aware that Intel and AMD CPUs aren’t interchangeable. You can’t fit an Intel CPU in an AMD motherboard, and vice versa.

You also have to make sure that your new CPU is compatible with the CPU socket on your motherboard. That’s relatively easy for AMD, as their consumer CPUs all use the same AM4 socket. You’ll be able to install most of their current CPUs in any AM4 motherboard, provided the motherboard has a BIOS that recognizes the CPU.

AMD AM4 socket

AMD AM4 socket. Source: Thomas Jensen

Intel, on the other hand, isn’t quite as generous. The company tends to introduce new motherboard sockets with every new CPU generation, forcing users to upgrade. The one recent exception is their latest LGA 1200 socket, which supports both 10th- and 11th-generation Intel CPUs. This isn’t a big deal when buying new. If you’re upgrading an older motherboard, though, make sure you check what socket it is and get a compatible CPU.

LGA 1200 socket

Intel LGA 1200 socket. Source: TechSpot

If you haven’t picked out a motherboard yet and aren’t sure how to, we’ve got a great guide on picking a motherboard that you can take a look at.

Clock Speed And Cores

Now that we’ve made sure your CPU and socket match, it’s time to get into the key specs to pay attention to when learning how to choose a CPU. Clock speed and cores are the heart of any CPU decision, so let’s go through both and discuss which of the two you should prioritize.

Clock Speed

Clock speed, often quoted in gigahertz (GHz), indicates how many cycles a CPU can perform in a second. It’s essentially how fast the CPU is.

Generally speaking, faster is almost always better. Higher clocks mean more cycles, which means that the CPU can perform more operations and calculations in a second. If you’re comparing CPUs from the same manufacturer and generation, the chip with the higher clocks will be faster.

It gets complicated when you compare CPUs from different generations or manufacturers. If that’s the case, you have to consider instructions per cycle (IPC). 4.0 GHz CPUs will perform the same number of cycles each second. However, their performance will differ based on how many instructions the CPU can execute during that cycle.

Let’s take Intel’s Core i9-10900K and AMD’s Ryzen 9 5900X. The Core i9’s 5.3 GHz boost clock should mean it’s faster than the Ryzen 9 5900X, which only has a 4.8 GHz boost clock. However, that’s not the case even in a single-threaded benchmark like SPEC2006.

Anandtech single thread CPU test

Source: AnandTech

That’s because AMD’s Zen 3 CPUs have better IPC than Intel’s components. Simply put, even though AMD CPUs can’t perform as many cycles as their competitors, they can do more within each of those cycles.

The tricky thing with IPC is that it isn’t listed in spec sheets, even though it’s more important than raw clock speed. So, if you’re comparing different manufacturers or CPU generations, you’ll need to do some research. Check reviews to see which of your shortlisted CPUs has the IPC advantage.

Gamers, and anyone running lightly-threaded applications (as in, ones that only use a few cores or threads), will benefit the most from high clock speeds and more IPC. Aim for a CPU with rated boost clocks above 4.0 GHz and you should be set for most tasks, including gaming.

You can even drop down to a CPU with fewer cores if it helps you get more single-threaded performance in your budget. If you only want to game, you won’t miss the extra cores most of the time.

Cores and Threads

Clock speed is only one side of the CPU coin. The other is how many cores and threads a CPU has. Cores are essentially smaller processors within the main CPU, with most consumer processors having anywhere from two to 16 cores.

Threads refer to how many simultaneous processes a CPU can handle at once. On lower-end CPUs, each core usually only has one thread. Most enthusiast-grade CPUs have something called multithreading, which means each core has two threads. This lets a core work on two separate tasks at the same time.

CPU hyperthreading graphic

Source: Intel

The upshot is better performance in multi-threaded programs. Multi-threaded programs spread their workload over many cores and threads, taking advantage of all the parallel processing that modern CPUs can do.

These multi- or highly-threaded applications include rendering and 3D graphics software like V-Ray or Blender and video encoding software like Handbrake. Core and thread count becomes particularly important if you’re using programs like these or constantly multi-tasking.

Clock Speed vs. Cores: Which Is More Important?

Choosing whether to prioritize clock speed/IPC or core count depends entirely on what you plan to do with your rig. If you only use lightly- or even single-threaded programs, you should make clock speed and IPC your number one priority. Games generally fall into this category.

Yes, game developers have started making sure their games spread the processing load over many threads. However, most game engines still want fast cores and high IPC above all else. A four- to eight-core CPU running in the 4 to 5 GHz range should be enough to last you for a good few years of gaming.

rdr 2 benchmark

Source: AnandTech

As these Red Dead Redemption 2 benchmark results show, the 16-core 32-thread Ryzen 9 5950X doesn’t really offer anything more in games than the six-core 12-thread Ryzen 5 5600X. Save your money and put it towards better components elsewhere.

On the other hand, if you’re looking to build a PC for serious multi-tasking and creative work, the sky’s the limit when it comes to cores and threads. Take V-Ray Next, for example. It gobbles up threads and really shines the more cores you throw at it:

Building a professional workstation for 3D rendering, animation, video editing, or computer-aided design? A CPU with 12 or more cores is almost mandatory. You can get by with fewer, but it’ll directly impact render and processing times. In the interests of minimizing the amount of time your PC’s tied up rendering or encoding something, we highly recommend getting a CPU with as many cores as you can afford.

Note that you should only get as many cores as will benefit your particular workloads. Sure, getting a 64-core Threadripper 3990X gives you serious bragging rights, but if your tasks don’t scale past 32 cores, then a 3990X will just be a load of wasted money. Before settling on a CPU, look into how many threads will actually benefit your programs. There’s no point in having more than you really can use.

Integrated Graphics

Integrated graphics get a bit of a bad rap, and it’s not hard to see why. Most integrated GPUs can barely game, with even 30 FPS at 720p being a challenge. Any decent dedicated GPU will run rings around an integrated equivalent in gaming. But not everyone wants to game, after all.

If you just need a PC for basic tasks, integrated graphics will do fine. Any Intel CPU without an “F” suffix will have integrated graphics. On the AMD side, you’ll have to go for one of their Athlon CPUs or a Ryzen APU like the Ryzen 3 3200G.

AMD’s APUs can also be handy for an ultra-budget gaming rig. Both the 3400G and 3200G will give you playable framerates at 720p. Just make sure your motherboard has a built-in HDMI or DisplayPort connector, and you’re set.

Another thing to note is that the “F” versions of Intel CPUs are slightly cheaper than their non-”F” equivalents. If you’re confident you’ll never need an integrated GPU, you can save some money here.

Overclocking

If you’re considering an Intel chip, think about whether you want to overclock. It isn’t for everyone, as it’ll take some elbow grease and decent cooling. But if you want to squeeze as much as you can out of a processor, it’s a great option. Unfortunately, Intel limits overclocking to its unlocked “K” chips like the i5-10600K and the i7-10700K, so you’ll have to pay extra for the privilege.

You can get some decent improvements from overclocking the 10700K to 5.1 GHz on all cores:

Hitman 2 CPU benchmarks

Note the 16% improvement in 99th percentile framerates. Source: Tom’s Hardware

We think you should almost always go for the “K” chip if you’re buying an i7. Getting almost free extra performance in some games and applications will help the CPU stay relevant for a bit longer. That’s pretty nice when you’re spending upwards of $300. Just make sure you’ve got a decent cooler picked out.

AMD doesn’t have any overclocking limitations, so you won’t have to think about whether you want an unlocked part. All their processors, from the lowly Athlon up to the monster Threadripper CPUs are freely overclockable. It might not be as worth it, though.

Overclocking Zen 2 CPUs will result in a lot more heat and less efficiency without significant performance gain. AMD’s new Zen 3 CPUs will boost to speeds above their rated maximums, so you may not even need to overclock. If you still want to, be aware that overclocking Zen 3 more complicated than Intel CPUs and even previous AMD CPUs.

So, What CPU Do I Need?

Learning how to choose a processor is great, but we also have some recommendations if you’re feeling overwhelmed. Let’s go through some common use-cases and CPUs we think would be suitable for each.

Budget CPU For Basic Tasks (sub-$100)

If you’re building a PC for everyday tasks and casual gaming, a low-end CPU with integrated graphics is what we’d recommend. Intel’s Pentium Gold G6400 is a good choice here. It costs well below $100 and will be perfect for browsing the internet and watching videos.

Intel Pentium Gold G-6400 Desktop Processor
$94.00

The G6400 has two cores and four threads clocked at 4.0 GHz.

07/23/2021 11:24 pm GMT

If you want an AMD CPU, we’d suggest something from their Athlon line. Unfortunately, the AMD CPU shortage has also hit their low-end CPUs, so even something like the Athlon 3000G is selling for $50 above MSRP as we’re writing this. Still, they’re worth a look when prices come back down.

AMD Athlon 3000G Unlocked Desktop Processor with Radeon Graphics
$99.99

The Athlon 3000G is another two-core, four-thread CPU and is clocked at 3.5 GHz.

07/23/2021 11:25 pm GMT

Mainstream Gaming CPU ($200-300)

Here, you’ll want a decent number of cores and a lot of single-threaded performance. The AMD Ryzen 5 5600X has both and is easily the best mainstream gaming CPU right now.

Unfortunately, prices are a bit out of control due to supply issues. We expect supply to improve sooner rather than later, though, so we’re still going to recommend it here. Keep an eye out for local deals; you might get lucky.

AMD Ryzen 5 5600X Unlocked Processor w/ Wraith Stealth Cooler
$289.99

The 5600X packs six cores and 12 threads, with a maximum boost clock of 4.6 GHz.

07/23/2021 11:26 pm GMT

Intel’s new Core i5-11600K is the standout CPU of its Rocket Lake series. With an up to 19% IPC improvement over its predecessors, the i5-11600K performs very similarly to the Ryzen 5 5600X in games and productivity. At MSRP, it offers compelling value. If you can’t buy a 5600X for a reasonable price, you won’t really lose out by buying one of these instead.

Intel Core i5-11600K Desktop Processor

Intel’s Core i5-11600K is a six-core, 12-thread CPU with a maximum boost clock of 4.90 GHz.

Content Creation and Streaming ($300-$500)

This is where CPUs with eight or more cores start making a lot of sense since you’ll be multi-tasking and likely running multiple programs at once. The AMD Ryzen 7 5800X will do a great job here. We’re starting to see 5800Xs selling for a lot closer to MSRP, which makes it a no-brainer purchase if you need its cores.

AMD Ryzen 7 5800X Unlocked Desktop Processor
$397.99

The AMD Ryzen 7 5800X is an eight-core, 16-thread CPU that runs at a maximum of 4.7 GHz.

07/23/2021 11:21 pm GMT

Intel’s best competing option, the Core i7-10700K, is decisively beaten by the Ryzen 7 5800X for games and productivity. But it’s at least $100 cheaper and offers decent bang for the buck. Intel’s new i7-11700K has hit shelves, but at an MSRP of $459, it’s too expensive for a CPU that only trades blows with the Ryzen 7 5800X at best.

Intel Core i7-10700K Unlocked Desktop Processor
$319.99

Intel’s Core i7-10700K has eight cores, 16 threads, and a max turbo frequency of 5.1 GHz.

07/23/2021 11:23 pm GMT

High-End Desktop ($800 and above)

If you need a huge number of cores for heavy-duty rendering, animation, or 3D work, AMD’s the only choice in 2021. Intel’s best high-end desktop (HEDT) CPU, the Core i9-10980XE, simply can’t compete with AMD’s offerings.

If you want a lot of cores without stepping up to a pricey TRX40 motherboard, AMD’s Ryzen 9 5950X is a brilliant choice. It has all the single-core grunt of its 5000-series cousins while ramping up the core count significantly. It’ll handle gaming, content creation, and even light workstation tasks with no issue.

AMD Ryzen 9 5950X Unlocked Desktop Processor
$849.00

The AMD Ryzen 9 5950X packs 16 cores and 32 threads that will boost up to 4.9 GHz.

07/23/2021 11:21 pm GMT

Your other HEDT option is to go full-on workstation with a Threadripper CPU. It’s hard to recommend a specific Threadripper CPU as it will really depend on your workloads. The Threadripper 3990X absolutely dominates in Blender but is “only” 35% faster than the 3970X in other tasks. So, we recommend the Threadripper 3970X as a solid middle-ground choice.

AMD Ryzen Threadripper 3970X Unlocked Desktop Processor
$2,135.00

The AMD Threadripper 3970X rocks 32 cores and 64 threads with a 4.5 GHz max boost.

07/23/2021 11:23 pm GMT

A Core Decision

To wrap things up, the most important things to consider when picking out a CPU are the core speeds, IPC, and the number of cores. After your budget, these are the most crucial specs. Sit down and outline what you’re trying to do with your rig, and go from there.

Knowing how to choose a CPU is an essential skill if you plan to build your own gaming or workstation rigs for years to come. The landscape will change and companies may rise and fall, but you can rest assured knowing what specs to look out for and prioritize will last you well into the future.

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