The central processing unit (CPU) is the brains of your PC. “Central” is right there in the name, after all. But every ruler needs a throne—and, when it comes to the CPU, the throne matters a lot. In fact, if your CPU gets the wrong seat, it won’t be able to rule over your computer after all.
CPU Sockets 101
The throne of which we’re speaking is known as the CPU socket, and it’s where the CPU sits in the motherboard. But not all sockets can accept all processors, and the biggest differentiator starts with the classic rivalry between AMD and Intel, the two major brands for CPUs in Windows PC.
Socket types are built into the motherboard and cannot be changed, and every part of the motherboard is tuned to work with particular generations of AMD or Intel processors. So, choosing between AMD and Intel impacts which motherboard models are available to you.
Where Is the CPU Socket?
Where you find the CPU socket can vary depending on the type of motherboard you’re using. Standard ATX motherboards (as well as Micro ATX and EATX) have the socket toward the top, while on a Mini-ITX board, it’s a little closer to the center.
It’s easy to tell what the socket is because it’s a big blank square and takes up a good chunk of space on the motherboard.
AMD vs. Intel Sockets: How to Tell the Difference
Now that we’ve found the CPU socket, we need to tell the difference between AMD and Intel, which comes down to the pins. CPUs communicate with the rest of the system through electrical connections carried through sets of pins. Depending on the processor, those pins are either on the socket or on the underside of the CPU itself.
For AMD, the pins are on the CPU, while the socket is a set of holes that the CPU slots into. Intel, meanwhile, leaves the pins on the motherboard, and the CPU has a set of contacts on the underside of the processor.
Where the pins are is the big difference between the two types of processors and how you can easily tell the two sockets apart, but there are other signs that you can look for.
Intel, for example, uses a retention bracket and latch with the bracket partially covering the seated CPU.
Unlike Intel, AMD uses a single retention lever. The seated AMD processor won’t be partially covered by a bracket.
CPU Generations Matter
Once you get to know the characteristics of both socket types, it’s hard to confuse the two. However, there’s more to sockets than just AMD vs. Intel. It also matters which generation of processor you use. Just because you have an Intel CPU, for example, doesn’t guarantee that it will fit into any old Intel-compatible motherboard, and the same goes for AMD.
The reason for this is that pin design and pin count impact the functionality of the system. Each pin is wired to communicate with a specific part of the system. Often, an old pin design cannot accommodate new features. For that reason, the socket design can often change between generations. For a more detailed explanation of pin design and socket changes, check out this Techquikie video on YouTube.
How Often Do New Socket Types Arrive?
AMD and Intel have to walk a fine line, of course. Many people want to buy the latest and greatest CPUs for their computers, but they don’t necessarily want to spring for a new motherboard every single time a new CPU comes out.
The two companies do try to accommodate users when possible, but they also won’t hesitate to move to a new socket type if they need to. At the time of this writing in July 2021, AMD’s most recent flagship lineup of CPUs is Ryzen 5000. It uses an AM4 socket, as do previous generations of Ryzen CPUs. But Ryzen 5000 supports only motherboard models built for Ryzen 5000 as well as most Ryzen 4000-compatible motherboards. Go back any further than that, and Ryzen 5000 won’t work despite the fact that older Ryzen motherboards are using the same socket.
There’s a similar situation on the other side. Intel’s most recent release at the time of this writing, Rocket Lake, uses an LGA 1200 socket, as does its predecessor, Comet Lake. Despite that seeming compatibility, however, there are some older Comet Lake boards rocking an LGA 1200 socket that won’t work with a Rocket Lake processor.
In both situations, this incompatibility has little to do with the physical socket itself, but rather, mostly concerns the surrounding technologies that support the CPU, such as the chipset.
Intel is also expected to come out with a new flagship desktop CPU series in late 2021 or early 2022 called Alder Lake. This new generation is expected to use a different socket once again to accommodate new technologies.
As you can see, sometimes, a particular socket will be around for years, while others only last for a generation or two. On top of that, sometimes, even the socket name isn’t a good guide to compatibility, as both Rocket Lake and Ryzen 5000 demonstrate.
How to Check Whether a CPU Fits Your Motherboard
With all of these little gotchas, it isn’t a simple task to keep a motherboard-to-CPU compatibility chart in your head. An easier alternative when you’re shopping for upgrades or a new PC build is to use websites such as PC Part Picker that can verify compatibility between the CPU and motherboard before you buy.
Socket types are a pretty simple concept to understand, but they can get confusing fast thanks to motherboard model types and compatibility issues. If you can identify AMD vs. Intel sockets, that’s good enough. For everything else, a little research will get you the rest of the way.
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