The CPU is the main processor chip in a computer. It gets attached to the motherboard in a very special socket and from this it can communicate with all other computer systems and send and receive billions of bits of data in a second.
In the past years, the processing power of a chip has improved substantially because of improvements in chip architecture and advancing technology. As a result, these changes have also been seen in the physical appearance of the chips, particularly with the terminals that connect the chips to their sockets on a motherboard.
However, if there is one thing that remains the same across many generation is the socket type. Here we learn about the different between two common sockets types i.e LGA vs PGA Sockets.
Basically, Land Grid Array (LGA) and Pin Grid Array (PGA) are the physical connectors and form factor through which the CPU connects with the motherboards. What is the difference between the two? let us learn below.
Also Read: LGA vs BGA Sockets
What is a CPU Socket?
Before we go deeper into these two of the common socket types, let’s first see what a socket is. The CPU socket is also known as a CPU slot.
This is the part of a motherboard that contains the necessary terminals and parts that hold the CPU in place.
This socket is easy to spot on many motherboards as it covers a large surface area when unoccupied and on it, you will see numerous terminals that make the contact points for those at the bottom of the CPU.
It provides the required shape and size for certain types of CPUs and as a result, you do not have the freedom to use whatever CPU you’d like on any slot.
This makes it even more important to identify the CPU slot on your motherboard before you go ahead and buy a certain CPU because if they don’t match then you won’t use it.
There are several socket types and here we’ll consider two popular ones, LGA and PGA.
LGA vs PGA Sockets
The LGA Socket
This Socket type is commonly used by Intel, a major CPU manufacturer. LGA stands for Land Grid Array and has been in use for over a decade.
With an LGA socket, the CPU itself has no pins, instead it has metal pads. The pins are located on the motherboard.
With the pins already placed on the motherboard, the CPU can just sit on top of the socket and can be held in place with the help of some mechanisms to prevent it from moving. This type of setup uses a pressure lever to hold the CPU in place.
LGA Socket CPUs
Since the contact pins are located on the motherboard itself, the CPU has no pins. Instead, the CPU has flat contact surfaces that coincide with the pins on the motherboard.
The pins on the board and these conductive surfaces close the circuit when a CPU is installed on the motherboard.
The conductive surfaces are also known as lands. They can be found at the bottom of the processor and are made of gold which has great conductive properties.
It is believed that this method evolved from an older socket type known as Leadless Chip Carrier. With this design, the contact used pads instead of pins for contact as well.
Intel CPUs that utilize this socket type includes the LGA 755, LGA 1155, LGA 1156 and LGA 1366. The first LGA processors by Intel came out in 1997 and they were the Pentium II and the Celeron.
Advantages of LGA Sockets
Because the pins are on the motherboard instead of the CPU, you have a little more leeway when handling the CPU because there’s no fear of damaging any pins.
The CPU is more durable because of this but of course, rough handling can still cause damages.
The PGA socket type is the direct opposite of the LGA socket. Pin Grid array sockets do not have pins on the motherboard itself. Instead, the pins are located at the bottom of the CPU itself.
These pins are what allow connection between the CPU and its socket and just like in LGA, they are designed to go into specific sockets.
The pins are made as sturdy as possible but they can still incur damages when the chip is mishandled so one of the few things you need to do as a precaution is to avoid installing this CPU into the wrong sockets. Some damage to the pins can be irreversible.
Once the pins are fitted into the appropriate holes, it is possible to secure the chip with a lever to ensure that it is firmly placed.
PGA socket types are commonly used by AMD for their microprocessors, although some of their entries such as the Threadripper use an LGA socket.
Installing a PGA socket is quite easy as the CPU can drop into place without the need of a lot of force. For this reason, PGA sockets can be referred to as the Zero Insertion Force (ZIF) sockets.
Advantages of PGA Sockets
With Pins on the CPU, fitting this chip into a socket can be as easy as aligning the pins with their holes and dropping the CPU in with very little force. Afterward, a lever can cause the socket to clamp the pins for firmer support.
Also, bent pins on the CPU can be easy to repair. You will need to be careful though.
Double Edged Sword
While PGA based CPU are very easy to install on to the motherboard, handling them can become an issue.
Putting pressure on a misaligned CPU or bending the pins on the CPU can result in irreversible damage.
AMD processors are often told off for using PGA as their primary topology since they are prone to accidents.
Similarly, Intel motherboard also told off due to their fragile pins on the motherboard. Once damaged, the pins on an LGA motherboard are almost impossible to fix.
Why Different Socket Types Exist
The main reason why different socket types exist is that CPU architectures are constantly changing. This is a good thing since new architectures are often introducing chips with lesser physical profiles and more power.
Due to these changes, there’s the need to constantly change the CPU itself. Also, the fact that there’s a competition between the two processor manufacturing giants, Intel and AMD, means that each works on different architectures that can have a lack of compatibility between them.
Here is a quick definition you can take note off:
- Land Grid Array
- Pins found on the Motherboard
- Process has metal pads
- Widely used by Intel
- Pin Grid Array
- Pins found on the processors
- Motherboard has a socket with tiny holes in them
- Widely used by AMD
Here we reviewed the difference between LGa vs PGA sockets. Like two opposite sides of a coin, LGA, and PGA sockets couldn’t be more different in appearance.
Nevertheless, they play the same role on a motherboard. They provide the CPU with a cradle and the necessary contact points for it to effectively communicate with every other device on a motherboard.
With each having its advantage over the other, the choice comes down to a matter of preference by the manufacturer.