Buying the Right CPU: The Ultimate Guide

Whether you’re upgrading a dated system or building a new PC from scratch, the choice of CPU matters a lot. Considerations like high clock speeds and core counts can make a whole difference in matters performance, resulting in a speedy system, butter-smooth gameplay and short execution of intensive tasks like video editing and transcoding. Also, the CPU you choose will ultimately dictate the motherboard options, since each processor runs a specific CPU socket and set of chips.

Again, like most aspects of mainstream consumer tech, you really have to settle on the best processor that’s available right now, but you can as well decide to wait and see what next-generation chips bring to the table. In November, AMD released the 16-core 9 3950X beast that offers even better performance than anything else in the market, but the Ryzen 3000 CPUs, especially the Ryzen 7 37000X and Ryzen 5 3600 have so far been our favorites.

Before AMD launched the new flagship, Intel launched the peppy 5GHz Core i9-9900KS in October, and it was a milestone as the best gaming CPU that combines good per-core performance ((aka IPC, Instructions Per Clock) with a high clockspeed, and then give you as many of those cores as possible. All that just shows how in just a year, so much has changed on the CPU front, but above all prices have been tame as both Intel and AMD attempt to outdo each other in new categories.

If you already know a lot about CPU specs and just want recommendations on PCs, check out our picks for best Desktop PC for gaming, Best Laptop for Gaming and the Best Laptops for college. But no matter the desktop processor you get, here are a few things to keep in mind.


Intel isn’t necessarily better than AMD: If you’re a mainstream user, for as long as you’re considering current-generation parts (AMD Ryzen 3000 or Intel 9th Generation Core), the myth that Intel is better than AMD is basically a wash. In real world usage, Intel’s processors tend to deliver slightly better performance on 1080p gaming on some modern titles (due to higher clocks), but AMD handles tasks like editing much better and faster.

Clock speed is better over core number: Having a system with higher clock speeds delivers snappier performance on simple, common tasks such as gaming, while more cores will get you through time-consuming tasks faster.

Always get the latest gen: Even when shopping on a tight budget, just go for the latest generation CPUs. You won’t save much money by going for older, previous-generation chips.

Simply for a full system: It doesn’t make any economic sense to get a strong CPU, then pair it with weak storage, RAM and graphics.

Overclock (if) absolutely necessary: Overclocking isn’t for everyone, only a few consumers need a higher-end chip, so if 3you don’t really need the extra power, it doesn’t make sense to spend extra cash for a chip you’ll never max out.

AMD or Intel: Which chip should you get?

Up until 2017, AMD always lagged behind Intel. However, after launching its Ryzen/Threadripper 2000 series chips, the company gained parity with its perennial competitor. Particularly, for those who run RAM-intensive applications, AMD’s latest Ryzen 3000 CPUs are ahead of the game, and if you factor the latest security patches that have arrived over the past year, AMD is clearly no longer an underdog. Still, some fans have strong opinions, but if you don’t have your choices cast on one brand or the other, you should be open to either.

That said, Intel still holds a slight lead in gaming at 1080p in some games, especially when you need to draw the most frames-per-second possible out of your graphics card to display on your high-refresh monitor. But in recent years, AMD has narrowed that gap considerably with its new Zen2 architecture, and it even tends to offer more cores and threads, making its CPUs ideal for professional-grade video editing and animation tasks.


How will you be using your CPU?

The excitement of spending more much on a CPU is ever present, but you might be better off saving some of the money for other components. The rule of thumb is: Determine the processor you need and max out the budget based on what you need your computer to do.

Basic computing: $50-$100 (£35-£80) range. If all you need is a chip that will let you watch videos, browse the Web, and do basic productivity tasks like word processing and light spreadsheet work, then a budget entry-level chip with two or four cores might be all you need. However, if you find yourself doing more than those tasks simultaneously, you’re better off with a stepped-up model or two. In that case, consider a Ryzen 3, like the AMD Ryzen 3 1300X or AMD Ryzen 3 2200G, or even Intel Pentium that are on the high end of this price range and an Intel Celeron or chips like AMD’s Athlon 200GE on the lower price tier.

Gaming: $150-$250 (£120-£220) range. If you’re shopping for a chip primarily for gaming, the least you can settle for is a midrange Intel Core i5 or AMD Ryzen 5 CPU. Remember, the graphics card you choose is more important when it comes to gaming over the processor, meaning you can save money by not getting a more powerful Core i7 or Ryzen 7 chip, then top it up with a powerful GPU.

Creative media work or overclocking: $250-$350 (£220-£320) range. For the professional creatives who need more cores or speed for tasks like video editing – or simply need a fast, capable system with extra overhead for power-intensive tasks, max out with a Core i7, core i9 or Ryzen 7 chip. These are the chips f choice if you’ll consider overclocking, though, AMD’s lesser Ryzen chips can be overclocked as well.

Raw workstation power: $400+ (£370+). If your work involves rendering 3D animations or processing 4K videos, or you deal with massive databases and complex math, but don’t have all day to wait for the tasks to complete, its time you considered an Intel Core X or AMD Threadripper CPU. These chips pack massive amounts of physical cores (up to 32 as of this writing) for extreme multitasking, gaming at high settings while streaming and editing and even time-consuming computing tasks. For business users, consider something like Intel Xeon (maybe the new Xeon W-3175X) or AMD EPYC processor, but those aren’t consumer friendly – or reasonably priced.

Which generation CPU is the best for you?

Almost every year, or so, Intel and AMD update their processor lines with new architecture. The current flagship generation for intel is the 9th Gen Core Series, like the Intel Core i7-9700K and higher-end Intel Core i9-9900K. On the other hand, AMD’s current chips are part of the Ryzen 3000 line, like the AMD Ryzen 9 3900X, Ryzen 7 3800X, and Ryzen 7 3700X. When checking out these chips, to see the model number, you can see the generation as the first digit of the four number (ex: the 8 in Core i7-8400 refers to eighth generation, or the 3 in Ryzen 7 3700X points to third generation).

One thing to note is that both companies tend to lag behind current architectures with their high-end, extreme chips. For instance, intel’s latest and greatest X-Series CPUs are still 7th gen while AMD’s second-generation Threadripper chips came out months after Ryzen 2000 CPUs had launched.

While you can always find older processor generations for sale, we can’t really recommend choosing one, unless you’re stuck with a motherboard that doesn’t support the latest chips. In fact, you don’t really save a lot of money by going with a last-gen processor, either. But you’ll often find yourself buying into a dated or dying platform.

Do you know how to read model names and numbers?

This is the most common aspect of decision making when buying a processor chip, but it’s not always easy to understand the numbers that make up a CPU product name form each brand. Both Intel and AMD classify their chips into three categories: Good, better and best, starting with Core i3/Ryzen 3, next up is Core i5/Ryzen 5, and ends with (for AMD, at least) with Core i7/Ryzen 7. Intel has recently released the Core i9-9900K at the top of its mainstream product stack, and they also. Have the extreme/premium tier like the Core i9-9980XE, priced at around $2,000 (£1,770). For the vast majority of users, these chips are beyond most people’s price ranges.

If shopping on a tight budget, Intel offers its Celeron and Pentium chips (Pentium is a bit faster) and AMD has he Athlon line. If your budget allows, you can max everything out with extreme high-end chips, where you have AMD’s Threadripper and Intel’s Core X series, along with the Core X/i9 and Xeon W (which we have mentioned above).

Now, what about the model numbers that comer after the 3, 5, or 7 (and 9 for Intel)? The first digit designates the product generation, such as;

  • Intel’s Core i7-8700 is an 8th generation core processor, and;
  • AMD’s Ryzen 2600 is a 2nd Generation Ryzen processor.

The rest of the numbers simply mark various models of the same base model in the line, with higher being generally better (offering more cores and/or higher clocks), while a “K” at the end of an Intel processor indicating it’s unlocked for overclocking.

Apparently, only a handful of mainstream Intel chips are “K” skus, while nearly all of AMD’s Ryzen processors are unlocked for overclocking – but they don’t require a “K” designation. However, an X at the end of AMD model numbers means higher clock speeds.

Do you really have to overclock?

Overclocking is the practice of pushing a CPU to its limits by getting it to run at higher-than-specced clock speeds, and is an art many PC enthusiasts enjoy practicing. But if you’re not in for the challenge of seeing just how far your chip can go without crashing, overclocking isn’t mostly worth the money for the average user.

Just picture this, in order to make your CPU achieve higher clock speeds than it is rated for out of the box, you’ll most likely spend extra on an enhanced cooling system and an overclocking friendly motherboard. As mentioned above, nearly all recent AMD chips are overclockable to some extent, but if you want to max out everything with an intel chip, you have to shell out more dollars for one of its K-series processors.

By the time you factor in all the extra costs of attaining an overclockable CPU, you’ll realize you’re better off budgeting another $50-$100 (£30-£70) for a chip that comes with higher clock speeds out of the box. And, even if you get all the right equipment, it’s still very easy to get a chip that doesn’t overclock well – or worse if you’re not sure of what you’re doing – you can easily damage your CPU or shorten its lifespan by pushing too much voltage through it.

What are the key CPU specs? Which one(s) should I care about?

If shopping for a CPU, there are lots of specs and numbers that. Can be confusing. Let’s break it down, and suggest what to look out for.

Clock speeds: Higher is faster. Measured in gigahertz (GHz), this denotes the speed at which the chip operates, with higher being faster. Most modern CPUs adjust their clock speeds up or down based on the task and their temperature, so you’ll come across a base (minimum) clock speed and a turbo (maximum) speed listed.

Cores: At least four cores are sufficient. These refer to the processors within the processor. In modern CPUs, you find between two and 32 cores, and recently AMD teased a 64-core chip with 128 threads (codenamed Rome, art of the newest Epyc processor) built for the datacenter and can handle server workloads. Most daily use processors contain four to eight cores, with each being able to handle its own tasks. Unless you’re shopping on a tight budget, you’re fine with at least four cores.

Threads: More threads mean better multitasking. 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 – but it isn’t. This is because 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). With more threads, you can comfortably multitask, and it means you have enhanced performance on heavily-threaded apps such as video editors and transcoders.

TDP: Higher TDP coincides with faster performance. The Thermal Design Profile (abbr. as TDP) is the maximum amount of heat that a chip generates (at stock speeds), measured in watts). Knowing that is important, for instance the Intel Core i7-8700K has a TDP of 95 watts, meaning 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 power for the same.

One thing to note is that CPUs put out significantly more heat when overclocked. As such, it’s good to know your TDP so you can get the right cooling and power equipment to support your CPU. Therefore, it goes without saying that a higher TDP often coincides with faster performance.

Cache: You should really be concerned about it. A processor’s on-board cache is the communication path that’s 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 has room but is slower, and L3 is spacious but is fairly sluggish. That means that 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.

Thus, when buying a CPU, you shouldn’t really put too much emphasis on cache size, because its not easy to equate to real-world performance, and there are lots of other factors to consider.

IPC: Not usually listed as a spec. The instructions per clock cycle (IPC) is heavily dependent on the CPU’s architecture, meaning chips from newer generations (ex. 9th Gen Core i7 versus an 8th Gen Core i7) will be better than older ones. Again, even if you have 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 produce different numbers of IPC.

In most cases, a CPU’s IPC is not listed as a spec and can ordinarily be measured through benchmark testing, so the best way is to learn about is to read reviews.


What do you need more: clock speed, cores or threads?

The answer to this question primarily depends on how your regular computing tasks. A CPU with higher clock speed translates to quicker responsiveness and program load times (keep in mind RAM and storage speed is key here as well). Higher clock speeds also mean single-threaded tasks (like audio editing and transcoding) can happen faster. Many popular games are still slightly threaded.

However, many modern programs can take advantage of lots of cores and threads. If your computing needs involve lots of multitasking or editing high-res videos, or do other complex, RAM-intensive, 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 sufficient enough.

Which socket does my motherboard need for this CPU?

Different processors require different socket types. If you already have a CPU but don’t want to replace it, they you’ll need to purchase a CPU that matches your board’s socket. Alternatively, you need to ensure that the motherboard you buy is compatible with your new processor.

For starters, AMD adopted a single socket -AM4- in its current-generation Ryzen and Athlon parts (barring Threadripper), and pledged to support that socket until 2020. That means you should, with a BIOS update, be able to install first-generalization Ryzen chip into second-generation (and maybe third-generation) Ryzen motherboard, and vice versa.

While AMD offers backward compatibility, Intel on the other hand, has this tendency of not supporting backward compatibility with its new chips and older motherboards, even if the socket is effectively the same. For instance, the Intel LGA 1150 and 1151 sockets differ by a single pin, and the version of 1151 specifically designed for 8th Generation Core chips is physically the same as that designed for previous 6th and 7th Generation Core processors. Even with the similarity, those older 11651-socket motherboards don’t work with newer 1151-socket CPUs, because (according to Intel) the newer chips (with more cores) have different power delivery subsystem needs.

It is a complexity that makes the future bleak, especially if you want to upgrade in the future, and it means you have to buy a newer, more-expensive motherboard for a current-gen chip, even if the more-affordable previous generation board bears all the features you want.

Our Take

Choosing the right CPU requires that you first ask yourself what you’re going to do with it, then see how much you can budget for it, especially after you’ve figured out how much you’re spending on other components like SSD, RAM, GPU and PSU. While processors are crucial in a PC, there are other considerations to make beforehand.

For example, 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. Again, while reading about specs like clock speed and thread count is important, the best measure of a processor’s performance comes from objective reviews, like those we write here on Digital Weekly.

Digital Weekly