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

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  • James_39
    Selecting the case is a bizarre thing to have in Step 1.Surely that would be best placed once all other components, including accessories, have been factored in? Otherwise you end up selecting components purely on the basis they fit in your case, not forgetting that some (most) cases don't support water cooling kits/pipes etc mentioned in Step 8.