The CPU matters a lot, whether you’re upgrading your existing system or building a new PC. Higher clock speeds and core counts can make a major difference in performance, providing a snappier system, smoother gameplay and faster completion of intensive tasks such as video editing and transcoding. Plus, the CPU you choose will also dictate your motherboard options, as each processor only works with a specific CPU socket and set of chipsets.
Also, like most aspects of consumer tech, you'll have to decide to buy the best processor that's available right now, or wait to see what next-generation chips bring to the table. AMD's Ryzen 3000 CPUs have continued to impress overall, while Intel continues to iterate on its 14nm Skylake-based architecture. This means that despite price drops on a per-core basis, Intel's Core i9-10900K isn't all that impressive, though the Core i5-10600K is much more appealing to those primarily concerned with gaming and mainstream computing tasks. Still, those Intel CPUs have been hard to find in stock since launch, while very good alternatives like the Ryzen 7 37000X and 3800X are readily available and ship with in-box coolers. The 16-core Ryzen 9 3950X brings even more performance to the "mainstream" CPU market, easily impressing us more than Intel's top-end mainstream 10900K.
If you already know a lot about CPU specs and want recommendations, check out our picks for best CPUs for gaming and best CPUs for performance / desktop applications and the best cheap CPUs of 2020, tested and ranked. We also have a list of the best chips on the market according to their CPU Benchmarks. But no matter which desktop processor you get, here are some things to keep in mind.
- AMD has overtaken Intel (in some respects): These days, you'll generally get more for less with an AMD processor, including a nice in-box cooler and more cores/threads. If you primarily care about gaming, Intel still generally does slightly better on 1080p gaming on some titles (owing primarily to higher clocks). And handles tasks like video editing faster. At many price points, so long as you don't care only about gaming, AMD delivers more cores and general performance (plus PCIe 4.0 on its latest chips), at a better value.
- For many tasks, clock speed is more important than core count: Higher clock speeds translate to snappier performance in simple, common tasks such as gaming, while more cores will help you get through time-consuming workloads faster.
- Get the latest gen: You won't save much money in the long run by going with an older, previous-generation chip unless that previous-generation chip is a Ryzen that hasn't been replaced by a current 3000-series part.
AMD or Intel: Which Should You Get?
Up until 2017, AMD was the clear underdog. But with its Ryzen / Threadripper series chips, the company has moved steadily toward performance parity with Intel. And in workloads that tax many cores, AMD's latest Ryzen 3000 CPUs have pulled ahead, especially if you factor in the security patches that have arrived over the past year or so. Some fans will have strong opinions, but if you don't have your heart set on one brand or the other, you should be open to either.
Intel still holds a slight lead in gaming at 1080p in some games, if you're looking to extract the most frames-per-second possible out of your graphics card to display on your high-refresh monitor. But AMD has narrowed that gap considerably with its new Zen2 architecture, and tends to offer more cores and threads, which makes its CPUs better for professional-grade video editing and animation.
For much more on this, see our Intel vs AMD: Who Makes the Best CPUs? feature.
What do you want to do with your CPU?
It's tempting to just spend as much as you can afford for a CPU, but you might be better off saving some of your cash for other components. Determine your processor type and max budget based on what you need your computer to do.
- Basic tasks: $50-$100 (£35-£80) range. If you’re only after a chip that will let you watch video, browse the Web, and do basic productivity tasks like word processing and light spreadsheet work, then an entry-level chip with two or four cores might be just what you need. But if you often find yourself doing more than one of those basic tasks at once, it would be better to step up a model or two. Consider a Ryzen 3, like the AMD Ryzen 3 1300X or AMD Ryzen 3 2200G, or Intel Pentium on the high end of this price range and an Intel Celeron or chips like AMD's Athlon 200GE on the low end.
- Gaming: $150-$250 (£120-£220) range. If you’re primarily interested in high-end gaming performance, you should opt for a mid-range Intel Core i5 or AMD Ryzen 5 CPU. Considering that the graphics card is more important for gaming than the processor, you can save money by not getting a more powerful Core i7 or Ryzen 7 chip.
- Creative media work or overclocking: $250-$350 (£220-£320) range. If you want more cores or speed for things like video editing—or you just want a fast, capable system with extra overhead for future computing tasks, splurge on a Ryzen 7 chip.
- Workstation muscle: $400+ (£370+). If you often find yourself waiting minutes or hours for your current system to render your 3D animation or 4K video, or you’re dealing with massive databases and complex math, consider an Intel Core X or AMD Threadripper CPU. These beasts offer massive amounts of physical cores (up to 64 as of this writing) for extreme multitasking (ex: gaming at high settings while streaming and editing) or time-consuming compute tasks. Business users can consider an Intel Xeon (like the recent Xeon W-3175X) or AMD EPYC processor, but those aren't consumer friendly--or reasonably affordable. For those not quite willing to step up to multi-thousand-dollar CPUs and platforms, AMD's 16-core Ryzen 9 3950X or 12-core Ryzen 9 3900X are both excellent alternatives that basically bring workstation-class performance to a mainstream platform.
What generation CPU do you need?
Each year or so, Intel and AMD upgrade their processor lines with a new architecture. The current generation for Intel is the company's "10th Gen Core Series," like the Core i5-10600K and higher-end Core i9 10900K. AMD's latest chips are part of its Ryzen 3000 line, like the AMD Ryzen 9 3900X, Ryzen 7 3800X, and Ryzen 7 3700X, or more recently the Ryzen 3 3300X and 3100. When looking at the model number, you can see the generation as the first digit of the four number (ex: the 8 in Core i7-8400 or the 3 in Ryzen 7 3700X).
How do you read the model names and numbers?
The jumble of brands and numbers that make up a CPU product name can be confusing. Intel and AMD both break down most of their chips into three “good, better, best” categories, starting with Core i3/Ryzen 3, stepping up to Core i5/Ryzen 5, Core i7/Ryzen 7, and Core i9/Ryzen 9. Intel has the Core i9-10900K at the top of its mainstream product stack, as well as extreme/premium tier like the Core i9-10980XE, priced at around $1,000. But for the vast majority of users, these chips are unnecessary and well out of most people’s price ranges.
For users on a tight budget, Intel offers its Celeron and Pentium chips (Pentium is slightly faster) while AMD has its Athlon line. On the extreme high-end, you'll find AMD's Threadripper and Intel's Core X series, along with the Core X/i9 and Xeon W (both mentioned above).
Now, what about the model numbers that come after the 3, 5, or 7? The first digit designates the product generation (Intel’s Core i7-8700 is an 8th Generation Core processor, and AMD’s Ryzen 5 2600 is a 2nd Generation Ryzen processor). The rest of the numbers just mark various models in the line, with higher generally being better (with more cores and/or higher clocks), while a “K” at the end of an Intel chip means it’s unlocked for overclocking. Only a handful of mainstream Intel chips are “K” skus, while nearly all of AMD’s Ryzen processors are unlocked for overclocking (no “K” designation required). An X at the end of AMD model numbers means higher stock clock speeds.
Should you overclock?
Overclocking, the practice of pushing a CPU to its limits by getting it to run at higher-than-specced clock speeds, is an artform that many enthusiasts enjoy practicing. But, if you're not in it for the challenge of seeing just how fast you can get your chip to go without crashing, overclocking may not be worth the time or money for the average user.
In order to make your CPU achieve significantly higher clock speeds than it is rated for out of the box, you'll likely spend extra on an enhanced cooling system and an overclocking-friendly motherboard. While nearly all recent AMD chips are overclockable to some extent, if you want to dial up an Intel chip, you'll have to pay extra for one of its K-series processors (which don't come with coolers at all). By the time you factor in all these extra costs, if you're not shopping at the top of the CPU stack already, you'd be better off budgeting another $50-$100 (£30-£70) for a CPU that comes with higher clock speeds out of the box. And remember, even if you do get all the right equipment, you could still get a chip that doesn't overclock well. Or worse if you don't know what you're doing, you could damage your CPU or shorten its lifespan by pushing too much voltage through it.
What are the key CPU specs and which should I care about?
If you're looking at a spec sheet for a given CPU, you'll see a lot of numbers. Here's what to look out for.
- Clock speeds: Measured in gigahertz (GHz), this is the speed at which the chip operates, so higher is faster. Most modern CPUs adjust their clock speeds up or down based on the task and their temperature, so you'll see a base (minimum) clock speed and a turbo (maximum) speed listed.
- Cores: These are the processors within the processor. Modern CPUs have between two and 64 cores, with most processors containing four to eight. Each one is capable of handling its own tasks. In most cases these days, you'll want at least four cores--or at least four threads (see below).
- Threads: This is the number of independent processes a chip can handle at once, which in theory would be the same as the number of cores. However, many processors have multithreading capability, which allows a single core to create two threads. Intel calls this Hyper-Threading and AMD calls it SMT (Simultaneous Multithreading). More threads means better multitasking and enhanced performance on heavily-threaded apps such as video editors and transcoders.
- TDP: The Thermal Design Profile/Power (TDP) is the maximum amount of heat that a chip generates (or should generate) at stock speeds, as measured in watts. By knowing that--for example--the Intel Core i7-8700K has a TDP of 95 watts, you can make sure you have a CPU cooler that can handle that amount of heat dissipation and also that your PSU can provide enough juice. But note that CPUs put out significantly more heat when overclocked. It's good to know what your TDP is so you can get the right cooling and power equipment to support your CPU. Also, a higher TDP usually coincides with faster performance, although things like process node size and general architecture efficiency come into play there as well.
- Cache: A processor's on-board cache is used to speed up access to data and instructions between your CPU and RAM. There are three types of cache: L1 is the fastest, but cramped, L2 is roomier but slower, and L3 is spacious, but comparatively sluggish. When the data a CPU needs isn’t available in any of these places, it reaches for the RAM, which is much slower--in part because it's physically farther away than a CPU's on-chip cache.
You shouldn't pay too much attention to cache size, because it's hard to equate to real-world performance, and there are more important factors to consider.
- IPC: Even if you have two CPUs that have the same clock speed and number of threads, if they’re from different companies, or built on different architectures from the same company, they will will produce different numbers of IPC (instructions per clock cycle). IPC is heavily dependent on the CPU's architecture, so chips from newer generations (ex: a Ryzen 7 3700X with Zen2 versus a Ryzen 7 2700X with Zen+) will be better than older ones.
IPC is not usually listed as a spec and is usually measured through benchmark testing, so the best way to learn about it is to read reviews.
What do you need more: clock speed, cores or threads?
The answer to this question really depends on your regular computing tasks. Higher clocks translate to quicker responsiveness and program load times (though RAM and storage speed is key here as well). Higher clock speeds also mean single-threaded tasks (like audio editing and certain older applications) can happen faster. Many popular games are still lightly threaded.
But many modern programs can take advantage of lots of cores and threads. If you do lots of multitasking or edit high-res videos, or do other complex, time-consuming CPU-heavy tasks, you should prioritize the number of cores. But for the vast majority of gamers and general-purpose computer users, a clock speed ranging from 3-4GHz with four to eight cores is plenty.
What socket does my motherboard need for this CPU?
Different processors require different socket types. If you already own a motherboard and don't want to replace it, you'll need to purchase a CPU that matches your board's socket. Alternatively, you need to make sure that the motherboard you buy is compatible with your new processor.
For help choosing a motherboard, see our 2020 motherboard buying guide.
With its current-generation Ryzen and Athlon parts (barring Threadripper), AMD has adopted a single socket—AM4. That means you should, with a BIOS update, be able to put a first-generation Ryzen chip into second-generation Ryzen motherboard, and vice versa. But due to limitations to the size of available data stored inside BIOS chips and the vast numbers of CPUs AMD has released on AM4, this issue has gotten much more complicated lately.
Intel, on the other hand, has a tendency in recent years not to support backward compatibility with its new chips and older motherboards, even if the socket is effectively the same. For instance, Intel’s socket LGA 1150 and 1151 differ by a single pin, and the version of 1551 designed specifically for 8th Generation Core chips is physically the same as that made for previous 6th and 7th Generation Core processors. But those older 1151-socket motherboards don’t work with newer 1151-socket CPUs, because (Intel says) the newer chips (which have more cores) have different power delivery subsystem needs. Note this just happened again with the move from 9th Generation Core (socket LGA 1151) and 10th Generation (socket LGA 1200).
This complexity is both frustrating from a future upgrade standpoint, and it means you have to buy a newer, more-expensive motherboard for a current-gen chip, even if a more-affordable previous-generation board has all the features you want. Here's a list of all the current sockets and their respective chipsets for reference.
Socket and Chipset Table
|Intel Mainstream||Intel Mainstream||AMD Mainstream||Intel HEDT||AMD HEDT (Threadripper)|
|Current CPU Sockets||LGA 1200||LGA 1151||AM4||LGA 2066||TR4|
|Compatible Chipsets||Z490, H470, B460, H410||Z390, Z370, Z370, Q370, H370, B365, B360, H310||X570, X470, X370, B550, B450, B350, B450, A320, X300, A300||X299||X399|
When choosing a CPU, first ask what you're going to do with it, then see how much you can budget for it after you've figured out how much you're spending on other components. Check our Best SSDs, Best RAM, Best Graphics Cards and Best Power Supplies guides for more details. While processors are important, there's no point in pairing a high-speed chip with weak graphics (unless you aren’t a gamer) or a slow, spinning mechanical hard drive. While reading about specs like clock speed and thread count is helpful, the best measure of a processor's performance comes from objective reviews, like those we write here on Tom's Hardware.
MORE: All CPU Reviews