CPU Sockets – CompTIA A+ 220-801: 1.2

The connection between the CPU and the motherboard has transformed many times through the years. In this video, you’ll learn about some popular CPU socket configurations on both CPU chips and motherboards.

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DIP stands for Dual Inline Package. That’s because on these older types of CPUs, you had these two sets of pins at the bottom that had to be very carefully pushed into the motherboard. This is an Intel 8088 CPU. It’s a very old CPU. And we don’t use this type of dual inline package any longer because it’s so easy to break these. Most of the time, you could line it up perfectly, be very patient, take your time, push it very carefully onto the motherboard with as little pressure as you could. But it still took a little bit of pressure to get it on there. And these small little pins would occasionally not go into the slot. They would bend. They would sometimes break. It became very easy to destroy a CPU just by trying to install it into the motherboard. So this did not make for a very easy method of installing and uninstalling these components from your motherboards.

Before installing any type of dual inline package– this is what the dual inline package connection looks like on a circuit board itself. This is from a token ring card. I had to find something really old because you don’t see these dual inline packages any longer. You can see it’s just a series of holes. You had to line it up perfectly, double check and triple check your work, and then push it in and hope that everything went in without too much of a problem. If you used too much force, you would break the pins off. If you didn’t use enough, you wouldn’t be able to push it all the way into the socket. It became very complicated to do. You had to practice quite a bit to make sure that you weren’t going to break any of these CPUs or anything else that you needed to install onto these circuit boards.

Fortunately, Intel saw that using this type of CPU package was not one that was very easy to work with. So they came up with another type called the Single Edge Contact Cartridge, or the SECC. We started seeing this with the Intel Pentium II. It just came in this big package here. It’s a big plastic connection that had this slot right at the bottom that you would use to plug into the motherboard. If we take off this plastic around it, this is what’s inside– is the CPU itself, and then some additional cache memory on the outside.

But here at the bottom, you can see that single slot. That was so much easier than working with those tiny little fragile pins. We could simply push this cartridge right on to the motherboard. It still took a little bit of pressure to get it on there. But it was very simple to install. And if we needed to uninstall, we simply pulled it right out. Made it very, very easy. The motherboard itself just had a single slot, and even had connections on the side. So you could slide it right on to the motherboard, and simply push it just a little bit. And pop it right into this connection. Very similar to plugging in any type of adapter card that’s on your particular computer. You can see it plugs right into that connection.

Once you put all of these packages together, you added on the heatsink. Because these CPUs got very hot and you needed to have some way to dissipate the heat out of this plastic cartridge. You had a pretty big CPU that was now plugged into your motherboard. It was very easy to plug it in and very easy to unplug it. But unfortunately, it took up a lot of room. And our processors began getting very, very small. They started shrinking in size. So we needed to find a different way to install our processors on to our motherboards that was easy to do, but it also didn’t take up a lot of real estate on the motherboard.

We started to see CPUs that had this type of packaging associated with it. This is an Intel Pentium III that uses something called a Pin Grid Array, or a PGA. And if you look at the bottom of the CPU, there are all these tiny pins at the bottom. That is the array of the pins that are arranged in that grid. So that’s our pin grid array. The top of the CPU looked the same as any other CPU. It’s the bottom piece that had all of those pins sticking out of it.

To use this CPU, we would take it and move it to a motherboard that had a Zero Insertion Force socket. This is called a ZIF socket. And it had this bar– this arm– on the side of it. We would simply, lightly place the CPU onto the exact pins associated with the socket on the motherboard. And we would simply close that arm to lock it in place. There was no pressure involved here whatsoever. So you didn’t have to worry about jostling the motherboard, or pushing too hard, or breaking any pins off. You simply laid the CPU right on top of this particular kind of socket, and you locked it down. Made it very, very simple to install and uninstall the CPUs. And it made it so that we didn’t have to worry about breaking other parts of the motherboard while we were performing that installation or the removal of a CPU.

These days, a lot of the CPUs use something called LGA. That stands for Land Grid Array. It’s the same idea that we had with the PGAs, but instead of the pins being on the CPU, we now have the pins on the motherboard. The CPU itself has no pins associated with it, which makes it a lot easier for the manufacturer to create the CPUs. The pins being on the motherboard means that we can’t ever damage pins that were on the CPU. Even though the pins were very small on the PGA processors, there was still a chance that you might damage one of those pins when moving it, when storing it somewhere else. They’re on the motherboard. So of course you have to be very, very careful with your motherboard. If you break a pin on the motherboard, then your CPU is not going to be able to work there either.

You’ll find these on a lot of the most modern processors– everything from the Intel Pentium IV, which goes way back, all the way up to the most modern, like our Intel Sandy Bridge. So if you have an i3, an i5, an i7 processor, it’s probably going to have an LGA type connection on the back of it.

Here’s what you would see on your motherboard. That CPU processor has all the little tiny pins sticking right up on the top. And you’ll notice the pins are much smaller than what we were using on the PGA side. We’ve been able to shrink these down smaller and smaller. And it makes it very easy to install these CPUs. If you look at them, the top of the CPU just looks like any other CPU. But on the bottom, it’s completely flat. All you have are these tiny copper connectors on the bottom that are fitting right on the top of all those little pins on the motherboard. This makes it very, very easy to install. There’s, of course, no force that you have to put onto the motherboard. And it makes it also easy to uninstall that if you ever need to remove it from a motherboard.