How To Build A PC

Step 2: Select A CPU

When it comes to selecting the right CPU, there are three factors to consider: performance, price, and usually to a lesser extent, power consumption. If you already have an idea of what your needs are, but still need some help with narrowing down your selection, our Best CPUs column is an excellent place to start. It includes general performance data and CPU recommendations for several price ranges, and if that’s still not enough, additional performance data on specific workloads can be found in our CPU Performance Charts.

Picking the best CPU for a new build starts with understanding your workloads. There are two main types of workloads to be considered: single-threaded and multi-threaded. Single-threaded workloads generally involve simple tasks such as browsing the web, word processing, and listening to music and usually do better on CPUs that have a higher per-core clock speed rather than a large number of cores.

Multi-threaded workloads include tasks like photo editing, video encoding, and some gaming, and usually benefit from processors with multiple cores. Additionally, technologies like Intel’s Hyperthreading are designed to accelerate certain multi-threaded workloads like video editing and encoding by allowing two threads to be interchangeably executed on a single core. Finally, although it may seem like a good idea to keep throwing more cores at multi-threaded workloads, there is a point of diminishing returns. Almost all consumer level software, including games, isn’t designed to run on an infinite set of processing cores, which is why Intel, the largest manufacturer of desktop CPUs, doesn’t offer mainstream CPUs with more than four cores.

Another option to consider when picking a CPU is overclocking. Overclocking is the process of raising the CPU’s clock speed past its targeted maximum, which often yields a measurable performance benefit. However, not all CPUs are capable of overclocking, and the ones that are capable often need a motherboard with a special chipset, which in turn costs more money. For Intel processors, you’ll need one of the more expensive K-series CPUs, which supports overclocking, and you'll need a motherboard with a Z-series chipset in order to overclock it effectively. AMD processors, on the other hand, are a bit trickier since they can all be overclocked. Generally, the more expensive chips will overclock better than their cheaper counterparts, and you’ll still need to ensure you have a motherboard that supports overclocking. Also, keep in mind that overclocking leads to increased heat and power consumption, which leads us to our last point.

Although power consumption isn’t exactly one of the primary concerns when selecting a CPU, it still has to be taken into consideration, especially if you plan on overclocking. Typically, the faster the processor, the more power it’s going to consume and therefore the more heat it’s going to produce, which also raises concerns about cooling and noise. While the stock cooling fans (those that come from the CPU manufacturer) may work fine with stock CPU speeds, they quickly become inadequate once the processor is overclocked, which means a more expensive air or even liquid cooler is in order. That extra heat also means the cooling solution is going to have to work harder and therefore louder, which can be undesirable in certain builds like HTPCs. In that case, a low-energy solution from AMD or Intel might be a better option.

Once you’ve figured out what your needs are, be sure to check out our list of the best CPUs for the money as well as the CPU reviews section; they should help you make a final decision on which CPU is best. Finally, if you’re stuck trying to make a decision or if you need more guidance, Tom’s Hardware’s CPU forums is a great place to ask questions and get the help you need.

MORE: Best CPUs
MORE: Best CPU Cooling
MORE: Intel & AMD Processor Hierarchy
MORE: All CPU Content

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  • AndrewJacksonZA
    "the power supply is actually one of the more important parts of a build"
    Thank you!!

    Or rather, let's do what the cool kids are doing and rather post a GIF:
    https://giphy.com/gifs/the-office-thank-you-michael-scott-1Z02vuppxP1Pa
    3
  • Eggz
    Great piece for a lot of first-time builders. This should have a sticky somewhere on the site so it doesn't get buried :-)
    5
  • jkhoward
    Quote:
    "the power supply is actually one of the more important parts of a build"
    Thank you!!

    Or rather, let's do what the cool kids are doing and rather post a GIF:
    https://giphy.com/gifs/the-office-thank-you-michael-scott-1Z02vuppxP1Pa


    Seriously, not enough people realize how import a good PSU is. I am working with someone is heavily overclocking an i7 and two 970 in SLI as well as 4 SSD and a few hard drives, a bunch of fans, with a 750W PSU.
    -2
  • jkhoward
    Also... I am digging the age of some of these images.
    3
  • blackmagnum
    This article brings back embarrassing memories. https://giphy.com/gifs/the-office-thank-you-michael-scott-1Z02vuppxP1Pa
    0
  • alidan
    Quote:
    Quote:
    "the power supply is actually one of the more important parts of a build"
    Thank you!!

    Or rather, let's do what the cool kids are doing and rather post a GIF:
    https://giphy.com/gifs/the-office-thank-you-michael-scott-1Z02vuppxP1Pa


    Seriously, not enough people realize how import a good PSU is. I am working with someone is heavily overclocking an i7 and two 970 in SLI as well as 4 SSD and a few hard drives, a bunch of fans, with a 750W PSU.


    unless i'm thinking wrong, isn't that within the power limits of a 750? im even assuming that each gpu is 300 watts and i know they shouldn't hit that even with the most aggressive of ocs

    granted there is a distinction between a good psu and a bad one, but im just assuming its a good one.
    3
  • chimera201
    Motherboard slots haven't evolved much. Wished every slot was like a USB slot
    0
  • turkey3_scratch
    Anonymous said:
    Seriously, not enough people realize how import a good PSU is. I am working with someone is heavily overclocking an i7 and two 970 in SLI as well as 4 SSD and a few hard drives, a bunch of fans, with a 750W PSU.


    Your point being... ?
    3
  • renosablast
    Steps 1 and 3 should be combined, and step 2 comes after 1 and 3. You better worry about the CPU and motherboard combo compatibility before you worry about a graphics card.
    -1
  • renosablast
    Sorry, meant steps 2 and 4 before 3.
    0
  • SR-71 Blackbird
    I love when you see a $1500.00 build with top quality components and then they have a $40.00 PSU listed with it.
    5
  • Outlander_04
    IMO the very first component selection for a gaming build should always be the .... MONITOR.
    Decisions on where and how to spend the rest of the budget can only be made once you know the resolution , and whether its 60 Hz, 144 Hz or whatever else is available
    1
  • MasterMace
    Gonna throw in my disagreement on the priority, mentioned nice and early in the article. The first thing you pick is never your case. There's 3 things you can decide to be your starting point when building a pc to make it a smooth ride; either, 1. Budget. 2. CPU 3. Graphics. By picking 1 of these 3 things as your starting point, you can have a very smooth build process. Does that mean you buy your case last? No, I've seen plenty of builds where the case arrives first as a way of storing the items, but when you want a solid build, your case is last priority, as it has no impact on your performance and restricts the size of your items.

    Even if you wanted to build an odd form factor, like an itx, you would still pick the cpu or the budget before the case.
    2
  • Anonymous
    Thank you for explaining ESD correctly. I have been annoyed with articles over exaggerating about ESD a lot. So just touching something metal can help? Well, next time I think I'll set a PC on my wooden desk instead of the carpet.
    0
  • kunstderfugue
    Quote:
    I love when you see a $1500.00 build with top quality components and then they have a $40.00 PSU listed with it.


    The XFX TS Bronze 550 comes down to $43 ish from time to time and that's a mighty fine PSU to power a single graphics card build.
    0
  • nitrium
    Quote:
    "the power supply is actually one of the more important parts of a build"
    Thank you!!

    While not unimportant, it gets far too much attention on the forum's here. PSU's are only relatively rarely the cause of issues, and I'll go out on a limb and say that virtually ANY modern 650W PSU (even ultra-cheap China garbage) will reliably power a single GPU and CPU, regardless of model or how much OCing you do to them.
    -2
  • Crashman
    Anonymous said:
    Quote:
    I am working with someone is heavily overclocking an i7 and two 970 in SLI as well as 4 SSD and a few hard drives, a bunch of fans, with a 750W PSU.


    unless i'm thinking wrong, isn't that within the power limits of a 750? im even assuming that each gpu is 300 watts and i know they shouldn't hit that even with the most aggressive of ocs

    granted there is a distinction between a good psu and a bad one, but im just assuming its a good one.
    You're exactly right. We've been using high-quality power supplies in most of our System Builder Marathon machines, and dual 970s was in one of the builds. The super-high recommendations you see from other sites are a response to most builders using mediocre-quality units.
    1
  • Crashman
    Anonymous said:
    Gonna throw in my disagreement on the priority, mentioned nice and early in the article. The first thing you pick is never your case. There's 3 things you can decide to be your starting point when building a pc to make it a smooth ride; either, 1. Budget. 2. CPU 3. Graphics. By picking 1 of these 3 things as your starting point, you can have a very smooth build process. Does that mean you buy your case last? No, I've seen plenty of builds where the case arrives first as a way of storing the items, but when you want a solid build, your case is last priority, as it has no impact on your performance and restricts the size of your items.

    Even if you wanted to build an odd form factor, like an itx, you would still pick the cpu or the budget before the case.
    Exactly wrong. The first thing people do is say "I want a LAN box" or "I want a media player" or "I want a big gorgeous office PC". They're picking a case SIZE when they make those FIRST statements, so size comes first in the discussion.
    1
  • beoza
    Quote:
    Anonymous said:
    Gonna throw in my disagreement on the priority, mentioned nice and early in the article. The first thing you pick is never your case. There's 3 things you can decide to be your starting point when building a pc to make it a smooth ride; either, 1. Budget. 2. CPU 3. Graphics. By picking 1 of these 3 things as your starting point, you can have a very smooth build process. Does that mean you buy your case last? No, I've seen plenty of builds where the case arrives first as a way of storing the items, but when you want a solid build, your case is last priority, as it has no impact on your performance and restricts the size of your items.

    Even if you wanted to build an odd form factor, like an itx, you would still pick the cpu or the budget before the case.
    Exactly wrong. The first thing people do is say "I want a LAN box" or "I want a media player" or "I want a big gorgeous office PC". They're picking a case SIZE when they make those FIRST statements, so size comes first in the discussion.


    I have to agree with you on this Crashman. Whenever I go to build a new system for friends or relatives I always ask what they're going for in terms of use. I like to go with the Form follows function principle which is that the shape of a building or object should be primarily based upon its intended function or purpose.
    0