What do you need to know before buying a CPU ?
PriceUsually, PC building or upgrading begins with asking, “What do I want to do?” Not this time. For all intents and purposes, you can perform all the same tasks with a $100 CPU that you can with a $500 one—the biggest difference is in how well you’re able to perform them. Therefore, deciding your budget is the first step, for purposes of
managing expectations as much as anything else. If you know right out of the gate that you may need 10 minutes to render a video rather than 20 seconds, you won’t be disappointed when you discover your processor’s limitations. Figure out the most you can spend on one component, and then see where that figure lies between (approximately) $100 and $1,000. The closer the chip is to the former, the slower it’s probably going to be. There are exceptions to this we’ll get to shortly, but it’s a good rule of thumb.
AMD or Intel?This question is vital when you’re upgrading, because AMD’s and Intel’s CPUs won’t work in the other standard’s motherboards, but it’s relatively inconsequential when you’re building a system for the first time. Though certain AMD and Intel CPUs do certain things better than others, those differences seldom matter much in terms of ordinary, everyday computing. So don’t worry that you’ll be cutting yourself off from certain tasks or aspirations if you choose one over the other. But one aspect of this choice is related to the previous issue: Every CPU in AMD’s consumer catalog is available for under $225, while the most expensive Intel chip runs $999. Does Intel deliver oomph to match the money? In most cases, yes—but you won’t necessarily be able to take advantage of it in every situation. Finding the right blend of performance and price for you may start with the CPU’s manufacturer, but never assume it ends there.
SocketOnce you know whether you’re buying an AMD or Intel CPU, and how much money you’ll have to spend, you need to think about the motherboard socket into which the processor will fit. These evolve over time as new technical developments and processes require new hardware, and the differences between them can be confusing. AMD currently has two main sockets: FM1 (for use with its APUs) and AM3+ (which, in addition to accommodating its current high-end Bulldozer-based CPUs, offer strong backward compatibility with several prior years’ releases). On the other hand, Intel’s mainstream processors now use the LGA1155 socket, whereas its enthusiast models use the LGA2011—and you can still find chips for older Intel sockets like LGA1166, LGA1366, and more. As mentioned, lower-priced CPUs for one socket type are usually going to be slower than others of that type, so if you think you may want to upgrade again soon, take a look at what else is available so you make the right decision.
Number of CoresIt wasn’t that long ago that the number of cores was an unheard-of attribute about processors—now, it’s the one you’ll want to focus on most. For all intents and purposes, every CPU these days feature from two to six processing cores, which all work together to crunch data and thus save you time. Not every software program supports this capability, and not all the ones that do support it equally. But software for particularly intensive tasks like photo and video editing will really benefit from a CPU with more cores. Of course, the more cores a processor has within the AMD and Intel families, the more it’s going to cost (AMD’s most expensive six-core CPU costs less hundreds than Intel’s cheapest, for example), but if you’re into heavy-duty computing you’ll probably find the investment worthwhile. It’s not impossible to find CPUs out there that have only one processing core, but on the off chance you do we’d recommend avoiding them. Sure, you’ll save a ton of money. But even dual-core CPUs are so ubiquitous and inexpensive now that it’s smarter to go with two or more cores than it is to select just a single-core chip.
Note: Related to the number of cores a processor has is the number of threads it can process. A thread is a string of instructions from one of the processing cores, and software programs that can manage more than one of these at a time will generally be faster than similar programs that can’t. (If you see the word “multithreaded” in a software review, this means the app can handle more than one thread simultaneously.) All AMD-based CPUs turn out one thread per core; some Intel processors use a technology called Hyper-Threading that mimics multiple threads within cores, giving you essentially twice the threads for your money. For example, though a four-core AMD CPU may be limited to four threads in an application, certain Intel quad-core models may be able to juggle eight in the same application—with a healthy performance boost (if not necessarily twice the speed).