An Overview of CPU Socket Types – CompTIA A+ 220-801: 1.6

| October 3, 2012

CPU sockets have changed a great deal through the years. In this video, you’ll learn how Intel and AMD socket types have changed with the evolution in CPUs.

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Review Quiz: An Overview of CPU Socket Types

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One of the main components of any computer is the CPU. And there have been a lot of different CPU socket types throughout the years. In this video, we’re going to look at socket types from both Intel and AMD, and we’ll see how all of those have evolved through the years.

Quite a number of years back, Intel introduced the Intel LGA 775. The LGA 775 has a lot of characteristics right in the name that we will need to know about. The LGA, meaning land grid array, that is the array of all of these little pins that are right here on the socket itself. And so the CPU chip itself does not have pins. All of the pins are on the socket. And this is 775 pins, so it’s very easy to remember that based on the name.

This was also called a Socket T. It stood for the Tejas core that ultimately was canceled by Intel. But they kept the name, so you may hear this referred to as either an LGA 775 or a Socket T. This was around in about 2004. We saw this in some of the late model Pentium 4 and Intel Core 2 Duo, some Xeon and some Celeron processors.

A successor to the LGA 775 was the LGA 1366. This had, as the name implies, 1,366 pins on it. Very, very different socket than the 775, you could also see this referred to as the Socket B. Now this came out in about 2008. And one of the very first Intel Core i7s used the LGA 1366 socket as its motherboard interface.

In 2009, Intel released another replacement for the Intel LGA 775. That was the LGA 1156, 1,156 pins on this LGA package. This was also called the Socket H1. What was nice about this particular technology is that it allowed Intel to create new CPUs that integrated the North Bridge right on the CPU itself. So you no longer needed that North Bridge memory controller right on the motherboard. Now it was integrated into the CPU for faster response times and faster efficiency when accessing memory.

The LGA 1155 has 1,155 pins. You may also hear this called a Socket H2. And although it’s very close to looking like an LGA 1156– there’s only one pin difference between those– there is not a compatibility between those chips. You can’t use them on different motherboards.

This LGA 1155 was the next generation of processor sockets for Intel. It was released in 2011, and it supported the latest generation of Intel Sandy Bridge and Ivy Bridge processors. Here’s a summary of these processor types. You can see, starting with the 775, all the way up to the 1155, all of these are land grid array, and you can see a summary of the release dates.

Also here, you can see the types of CPUs that were expected to be used in these particular sockets, starting with the Pentiums, going through the Nehalem code name that Intel used for a series of chips, all the way up to the Sandy Bridge and Ivy Bridge chips. And the last column here shows you the type of memory that’s supported on each one of these socket types.

Now let’s change our focus to the evolution of how AMD has changed their sockets through the years. Let’s start with the Socket 940. These names are so easy to remember, because this one has 940 pins. And unlike the Intel LGAs that we were looking at, you’ll notice this is a different format. This is a pin grid array, a PGA, where all of the holes for the processor are on the motherboard. And the processor itself is a zero insertion force package, where it has all of the pins that fit into the holes that are on the motherboard, and it locks down was zero force by using this locking arm on the side.

This came out in about 2003. It was used for the Opteron and the Athlon 64 FX chips, so the 64-bit servers was the primary focus for the Socket 940. The Socket 940 supported CPUs that could use DDR RAM, so we’re going back to 2003 when we were using the Double Data Rate RAM and not yet getting into the DDR2 or the DDR3 memory.

In 2006, AMD released a new socket called the Socket AM2. This socket also had 940 pins on it, but it was not compatible with the older Socket 940 previous to this version. One significant change in the Socket AM2 is that it allowed processors to use DDR2. And because you were not able to have that backward compatibility with the Socket 940, we weren’t able to use DDR memory, only DDR2 memory with the Socket AM2.

In 2006, about the same time the AM2 socket was released, AMD also released Socket F. This was an LGA package so a little bit different than the PGA package we were seeing earlier. And the Socket F had 1,207 pins. The Socket F was really designed for servers. The CPUs that would use the Socket F needed to use registered DDR2 memory. That’s a buffered memory that had very high throughput. And at the same time, these particular CPUs also had a faster throughput on the front side bus so that you could send and receive information to that memory that much faster.

In 2007, AMD introduced an upgrade to the Socket AM2, called the Socket AM2+. As the name implies, it was a minor upgrade. Physically it looks identical to the Socket AM2. The AM2+ processors can potentially operate on an AM2 motherboard. Usually, it would require a BIOS change to the AM2 motherboard. And AM2 processors were designed to work on the AM2+ motherboard. This was a minor upgrade. There was faster communication on the front side bus. There was better power management. And it really positioned AMD to have faster processors for their computers.

AMD’s next generation of processors used a new socket called the Socket AM3. This was a 940-pin socket, again using that PGA-ZIF package, and it effectively upgraded and replaced the AM2 and the AM2+ sockets. And what was interesting about this socket is that there was some backwards compatibility. You could take a processor designed for an AM3 and put it into an AM2 or AM2+ socket motherboard. Usually, it required a BIOS upgrade.

One major advantage of using the Socket AM3 is that the processors used were able to use DDR3 memory so you could have higher throughput and faster performance. As you can see, AMD tends to make minor changes to their sockets so that you can, in some cases, take the processor from your older motherboard and use that in your newer motherboard. And so they released in 2011 the Socket AM3+. This had 942 pins and, again, had that PGA package.

And again, what’s nice about this is the upgradeability. You could take your AM3 processor, buy a new AM3+ motherboard, and use that processor in the motherboard. AMD did not support taking the AM3+ and moving to the older motherboards, but you could certainly take your older processor and move it up to the faster technology on the motherboards that supported AM3+.

In 2011, AMD also introduced the 905-pin Socket FM1. The FM1 allowed processors that had higher performance. They used DDR3 memory. And it did things like take the PCI Express controller and move it onto the CPU itself.

Here’s a summary of the AMD sockets, from the 940 up to the FM1. You can see almost all of them used a PGA, except for the Socket F. The release dates are also in here and the type of processors that were used on those sockets. And you can see the type of memories changed a lot over the years, going from a DDR dual channel all the way up to a DDR3 dual channel.

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Category: CompTIA A+ 220-801

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  1. Marco says:

    Thank you for the great overview! It would be interesting to see a comparison between Intel and AMD processors.