When it comes to upgrading your system, few components are as important as the central processing unit (CPU). You might think of this as the computer’s brain — and that metaphor works. The CPU is responsible for performing the calculations the computer needs to operate.
Because of this, it might be the most important component of your system — no
matter how much RAM you have. When you’re upgrading your PC or building a new one, knowing how to choose a CPU is a crucial part of the process. There are several things you’ll want to take into consideration when choosing a CPU.
When it comes to CPU, a lot of people don’t know where to begin. They might have an idea about what they need, but the very existence of a seemingly endless array of possible choices makes choosing one a daunting task. There are ways to narrow your options from the outset, but there’s also the other extreme – when you know every technical detail but you’re still baffled as to which CPU is best for your system. If that sounds like you, don’t worry – we’ve got some pointers for you below.
Buying a new CPU can be a daunting task, whether you’re building your own computer or simply upgrading. There are so many specifications to look over that it’s easy to become confused. You ask yourself: what are cores, threads, and clocks? Why does Total Cache matter and how do I calculate my cache ratio? And why does everybody keep using the word ‘efficiency?’ Well don’t worry, because we have been there too, and we are here to help.
When looking to buy a new CPU, you might be overwhelmed. You see the different brands, the numbers, and then all the jargon that makes even me shudder a little bit. There are several different factors you have to take into consideration, and it can be hard to know where to start. The following guide should take some of the stress out of choosing a new processor. I’ll begin by explaining what CPUs are before getting into the details of what it is that separates them from each other.
How to choose a CPU: AMD vs. Intel
For those of you who are brand new to computers and have just decided that it’s finally time to build your own system, first let me say: Welcome to the club. The amount of money you will save under this scenario is huge. Even better is that setting up a PC is pretty darn straightforward these days, as long as you don’t go overboard with over-clocking. Today we take a look at AMD vs Intel and break down the pros and cons for each so you can make an informed decision when choosing your CPU.
But when it comes to deciding which CPU is the best, you’re likely to get a sense of deja vu. It feels a lot like the debate over AMD vs. Intel from about 15 years ago: people have been making the same arguments and complaints for decades now. Does AMD have better prices? Are Intel CPUs overpriced? It all depends on the individual models in question.
AMD and Intel build processors that make it possible to do everything you want to do in your new home or office PC. While they both build near-identical processors that have many of the same features, they have some differences, and understanding their strengths and weaknesses is going to help you make the best decision for your new computer.
You’re probably here because you’re looking to buy a new CPU and aren’t sure whether Intel or AMD is the way to go. Well, it all comes down to personal preference and the workload you want them to handle. Both companies have processors that cater to every need and budget, so I’m going to highlight the differences between them and then advocate my preferred CPU.
So you’ve built your custom computer and it’s time to install an operating system — but what about your CPU? You see, you cannot use a graphics card from AMD or an Intel processor in a motherboard made for the other company. This can cause problems if you don’t know what you’re doing.
CPU Names and generations
Naming schemes are used to describe a processor’s features and how it relates to processors in other generations. And, like all tech product marketing, the schemes can get tangled pretty quickly.
Generations and tiers are essential to understanding CPU specifications, but what do they mean? What generation a processor is from will be the most important. With each new generation, processors become more efficient. A second tier system will always perform better than a first tier one, even if they are both from the same generation. But it’s also worth noting that while first tier parts might not be as powerful as second tier ones when it comes to raw performance, they can still do the job for simple tasks.
It was once thought that a processor should be judged on its individual merits, but this quickly turned out to be a flawed way of looking at things. It isn’t just older processors that are slower than the newest models, but different members of the same generation can also have vastly different performance levels. This is what makes it key to understand something not only about your individual processor but also about the generation that it belongs to along with the tier it sits in as part of that generation.
You’ve probably seen labels next to CPU names like AMD Ryzen 7 3700X or Intel Core i7-9700K. The first number in a processor label tells you the generation which the processor belongs to – for example, Intel’s latest generation of processors use 8th gen chips. The second number tells you the specific model within that range. For example, Samsung’s M2070-DB01 sports a 2.0 GHz Intel Celeron Processor U3400.
The labeling of these chips is also rather muddled. You’ve probably noticed that each one has two sets of numbers: the first and second sets go up as you move from left to right, and the third generational number goes up as you move down. Oddly, 3 refers to third-generation Ryzen 7 processors, while 2 refers to second-generation Ryzen 5 processors. And the X in each model number refers to an Austrian-sounding “extreme performance” designator.
When it comes to processors, both manufacturers use a similar code for the generations of processor. The first number denotes how many generations it has been since the architecture was first introduced, and the second number notes how many generations have passed since the previous processor generation. So a 7th-generation processor is one that’s on its seventh round in the marketplace. The more important number is usually the first.
Still with me? Good! Now that we know how to read the processor’s name, let’s talk about the rest of that info on the label. For example, if you see a lot of numbers and letters after the model number, you’re looking at an unlocked processor. What does that mean? It means that you can overclock it. Overclocking is when you push your CPU to work faster than its rated specs. It’s not for the faint of heart, though — overclocking comes with a risk of pushing your CPU too hard, leading to a permanent hardware failure. That’s why it’s best left to experts . . . or people like you who have read this guide 🙂
You may have noticed that some Intel processors have a couple of suffix letters at the end of their names. For example, the Core i7-4790K has the full name of Intel(R) Core(TM) i7-4790K CPU. The part we’re interested in is “K”, which shows that this processor is an unlocked part for overclocking. Not all processors are unlocked, so you will want to double-check before buying a new processor.
- G1-G7: Graphics level
- E: Embedded
- F: Requires discrete graphics
- G: Includes discrete graphics
- H: High performance optimized for mobile
- HK: High performance optimized for mobile, unlocked
- HQ: High performance optimized for mobile, quad-core
- K: Unlocked
- S: Special edition
- T: Power-optimized
- U: Mobile power efficient
- Y: Mobile extremely low power
Cores and threads
Cores are like individual processors of their own, all packed together on the same chip.
There are a few things to consider when thinking about cores and threads, the two main factors you need to look at when considering the number of cores in a processor. Cores are bits of central processing units (CPUs) that work together. They do this so they can run their own bit of software and do it at the same time as others within the CPU without having to wait for them.
Typically, one core will perform each action and software can only use one core at a time, with more and more being able to be used for more complex tasks once modern parallel computing techniques have been developed in software. Some systems manage to take advantage of two or more cores at once; those are termed dual-core or, for example, quad-core if all four parts of the CPU can be run in parallel by any software.
When it comes to CPUs, there are two comparison points that you’re likely to see highlighted: number of cores and threads per core. Cores are an easy comparison point because they have a largely uniform measurement of benchmark performance across different architecture families. The problem with threads is that modern processors use simultaneous multithreading (SMT) and hyperthreading to boost their performance by a significant margin.
The number of cores and threads is one indicator of performance, but it’s not the only thing you should pay attention to. You should also think about clock speed when buying a new processor.
A CPU’s threads are the number of tasks that it can conduct at any one time, whether they be graphics rendering or data computations. More threads aren’t always better, but generally more is better unless you need a specific number that is higher than your motherboard supports. The number you see next to things like 4-core and 8-thread is the threads. Each core can handle one thread at a time but modern chips support hyperthreading, where each physical core can exploit idle parts of it to create additional threads. In a 4-core processor like the i5–6600K, each core supports 2 threads. Other chips can support more cores and all the threads they can handle. Try to get a CPU with more than 4 available threads if you’re interested in gaming or content creation.
Running a game requires several different types of hardware to work together, including your video card and system RAM. Games are most often made to run on a quad-core CPU, but some game developers will code their programs to put even more strain on your system’s processor. While running a game like Assassin’s Creed Odyssey isn’t exactly the same as running a benchmark program, it still puts enough load on the processor where performance can be measured in reasonable time periods.
If you’re a gamer, you should choose a CPU with at least four cores if you have the budget. Six cores give some additional headroom in a few games, but few modern games (and no new releases) will ever use more than six logical CPUs. Namely, the only game that benefits from an eight-core CPU is Star Citizen 2.0 , and using more than six cores doesn t really give any major gains in that game. Eight-core CPUs are also much more expensive than their lower core count counterparts for very little performance increase.
If you’re not a video editor or don’t work with large databases, you may wonder why you would need a CPU with more than four cores. After all, it’s not like your single-threaded Word or image editing application is going to push your current CPU to its limits. So what good are so many cores? Well, the numbers get a little fuzzy here, but we can make some generalizations. If you run the same applications most of the time, then it may be possible that eight cores will help speed things up.
CPUs clock speed
The speed of your CPU can affect many aspects of your computer — from how fast it starts up, how quickly your programs run and how much you can multitask. However, it can be confusing to know what type to get for your needs. It’s vital to take into consideration your future needs along with how fast you need your computer to run now. Along with processing power, the speed of the bus that connects the processor to the rest of the computer plays a big part in its overall performance.
Everyone wants a faster processor. The question is, how much of an impact does clock speed really have on performance? Yes, more MHz (megahertz) is better than fewer megahertz, but for single-threaded tasks like surfing the web or writing emails, the difference between 2.4 and 2.6 GHz is negligible. In fact, many modern processors will run at less than their maximum clock speed in order to save power and reduce heat.
For many people, deciding between the Intel i9-9900K and AMD Ryzen 2700X comes down to budget. The i9-9900K is a more powerful CPU in more ways than one. It has eight cores compared to the 2700X’s six, as well as 16 threads to the Ryzen CPU’s 12. On top of that, the 9900K has a higher base clock speed (3.6GHz) than the 2700X (3.7 GHz) and so can maintain a higher speed during periods of heavy use or benchmarking. If you want to build a PC that won’t trip over itself during heavy workloads, Intel’s chip should be your answer. The 9900K comes at a cost, though; it’s expensive versus its AMD rival- starting at $488 compared to $329 for the 2700X.
When talking about processors, you’ll see clock speed (measured in gigahertz [GHz] or even terahertz [THz]), and core count (measured in cores and threads) plotted against each other. The higher the clock speed, the faster a processor can crunch numbers. The more cores/threads it has, the more work it can handle at once. But just because it has more cores/threads doesn‘t mean it will be faster.
Higher core counts give the chip bigger pipes to work with and makes more of a difference when tasks involve working on large quantities of data. That’s what usually means having a lot of cores isn’t as important as having very fast ones. That isn’t always true, though, which is why I say “usually.” If you want the best CPU, clock speeds will come into play. For example, you don’t necessarily want to choose a 6-core processor if you can get an 8 or 10-core processor that runs at a higher frequency instead.
Power and thermals
If you’re looking to spend more than $800 on a desktop CPU, performance is the most important factor before deciding on a new chip —after all, if you can’t do what you want to do faster than you could with an older PC and slower processor, what’s the point in upgrading?
Performance is king. In a perfect world, that’s the only thing you’d pay attention to when buying a new computer. Big numbers are fun and exciting, they look good on paper, and will make your friends jealous. Heat and power consumption aren’t exactly sexy, but they matter.
As you’re likely aware, all (OK, nearly all) CPUs are designed to manage the flow of electricity and heat that come with their operation. Used in the correct manner, they will allow information to be processed much more quickly than otherwise — but used inefficiently, they’ll overheat and possibly damage their surrounding hardware.
Finding out how much power a processor uses is not a straightforward process. Power and thermal data is typically only provided by the manufacturer in the form of Thermal Design Power (TDP). TDP is expressed in watts and gives you an idea of approximately how much power a CPU will require to run safely, but without a degree of guesswork on behalf of the user.
The TDP rating is useful information when buying a CPU, but it’s only a rough guide. AMD and Intel have several different models in each generation with differing power and thermal demands – taking a universal ‘average’ figure for the entire range can sometimes give you an inaccurate picture of how much power a part might really need.
When buying a new processor, it’s easy to get bogged down by numbers like clock speed and core count. Most of us are more than familiar with megahertz and gigahertz, but these are the wrong units to be considering when looking at processors.
The real metric you need to be looking at is thermal design power (TDP). While there is some overlap between TDP and power consumption, the latter is based on how much juice your CPU will draw at top speed, while TDP is based on how much it’ll need in order to run safe while idling. If you’re only going to be streaming media, then the amount of power your CPU consumes isn’t going to be that important. However, if you’re trying to build a powerful PC then both matters are crucial.
Conventional laptops consume around 15-45 watts of power, depending on their CPU and GPU demands. If you’re upgrading to a gaming system, you can expect a desktop to use somewhere between 65-125W. CPUs are the most demanding component in taking up the most power at 45W, with GPUs specifically straining the supply if you max them out. You might be inclined to think that processors used in highly-demanding workstations are the biggest energy hogs, but you’d actually be wrong. Traditional desktop computers use anywhere from 65W to 100W of electricity at peak load, depending on what they’re doing.
The new Haswell processors are more than 40% more power efficient than previous Intel parts, with serious implications for the functionality of upcoming ultraportables.
Some thoughts on How to choose a CPU?
Choosing a CPU is a big decision. Especially if you’re buying a new gaming PC. If you get the wrong CPU, your new PC might be less powerful than you hoped and this can be frustrating. If you get an underpowered CPU, there’s often little that can be done to improve gaming performance in the future. So, how do you know what to buy? It’s not difficult, but there are more options out there than many people realise. The first thing to consider when picking a CPU is how many cores and threads you need.
Which CPU do I choose? That’s a tough question, especially when you’re dealing with the sort of budget builds that find their way onto our Best gaming PCs page. The good news is that despite all the different numbers—from core count to clock speed—pretty much every new processor on the market today performs well enough to handle whatever you throw at it.
You don’t need to spend any more than you have to in order to get a system that can run modern games with decent frame rates and low-medium settings. Historical data will always tell us something about how two or more CPUs compare to each other, but it’s not very useful when we want to know which CPU is best for one task or another. Luckily for us, there are lots of independent reviews out there, and I recommend checking them before you make a final decision on your next purchase.