Both LGA and PGA are basically types of surface mount technologies (SMT) that define how the processor will mount on the motherboard.
LGA stands for Land Grid Array and PGA stands for Pin Grid Array. LGA based CPUs have flat surface contacts where as the PGA CPUs have pins for interfacing with the motherboard.
Different manufacturers use different techniques and there are pros and cons to both techniques.
In the current market, Intel primarily uses the LGA technology whereas the AMD uses the PGA technology for their processors.
The type of surface mounting a CPU uses also affects how the CPU socket is designed on the motherboard as well. In the following text we further compare LGA vs PGA.
Note there is also the BGA (Ball Grid Array SMT). You can read more about this here: LGA vs BGA
LGA vs PGA Physical Differences in Brief
As can be seen in the image above, the PGA socket have visible pins that go directly into the CPU socket.
The LGA CPUs, however, are the polar opposite in terms of how they mount on the socket.
With the LGA CPU, the pins are located ON THE MOTHERBOARD instead of the CPU.
Also Read: Why is a Motherboard Important?
What is a CPU Socket?
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.
For example, if your motherboard has an LGA1151 socket, then an LGA1200 CPU would not work. Intel 8th and 9th gen CPUs use the LGA1151 socket whereas the 10th and 11th Gen use the LGA1200 socket.
AMD uses the PGA based AM4 socket. The socket on the motherboard for PGA CPUs does not have pins, instead it has tiny slots for housing the pins of the CPU.
Also Read: What CPU is Compatible with My Motherboard?
LGA vs PGA
LGA Surface Mounting Technology
This Socket type is commonly used by Intel.
With an LGA socket, the CPU itself has no pins, instead it has metal pads. The pins are located 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.
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.
Intel is the Primary User of LGA Based CPUs
The first processor by Intel to use the LGA SMT were the Pentium II and Celeron CPU in 1997.
Currently there are are three popular LGA based sockets.
The current Intel socket for the mainstream DESKTOP CPUs are as follows:
- LGA 1151 for 7th, 8th and 9th Gen Core, Pentium and Celeron CPUs
- LGA 1200 for 10th and 11th Gen Core, Pentium and Celeron CPUs
For Intel Workstation CPUs:
- LGA 2066 for 10th Gen Intel Core Extreme processors like the Intel Core i9-10980XE
The number after LGA tells you how many contact pads the CPUs has and how many corresponding pins the motherboard CPU socket has.
AMD has Started Using LGA based CPUs as well
Most of the newer workstation and server grade AMD CPUs have started to utilize the LGA based surface mounting technique.
The latest workstation grade Ryzen Threadripper and Ryzen Epyc server based CPUs use the sTRX4 and the SP3 socket respectively both of which are LGA4094 sockets.
Also Read: How to Test Motherboard Without CPU?
PGA Surface Mounting Technique
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 on the bottom of the CPU itself.
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, such as the popular AM4 socket for their Athlon and Ryzen series processors, although as mentioned earlier, some of their newer entries such as the Threadripper series CPUs may 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.
Double Edged Sword – Be Careful with the Pins
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 motherboards are also told off due to their fragile pins on the motherboard. Once damaged, the pins on an LGA motherboard are almost impossible to fix.
Also Read: How to tell if CPU is Bad or Dead?
Advantages of LGA CPUs
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.
Hence the CPU is more durable here.
Disadvantage of LGA CPUs
One of the major disadvantage of LGA is with installing the CPU. You have to make sure that CPU is properly aligned before you lock the CPU in with the lever.
Applying the pressure with the locking lever on a CPU that is not aligned to the last 1mm can damage the pins on the motherboard socket.
Advantages of PGA CPUs
With pins on the CPU, fitting this chip into a socket can be as easy as aligning the pins with their corresponding holes on the motherboard socket. The CPU just slides in by itself without any pressure applied.
Also, here the motherboard is more durable since it does not have any pins that can be bent or damaged.
Disadvantage of PGA CPUs
The biggest disadvantage with PGA is the that a damaged pin on CPU can effectively render it useless.
You have to very careful in handling a PGA CPU.
Breaking CPU Pins can be FAR MORE EXPENSIVE Than Breaking Motherboard Pins
In my personal opinion, LGA based CPUs are superior to PGA.
A damage to pins on a CPU can be more expensive than damage to the pins on a motherboard.
A CPUs is often twice, if not multiple times, as expensive as the motherboard. I would rather have less durable motherboard than a less durable CPU.
Here is a quick definition you can take note off:
- Land Grid Array
- More durable CPU
- Pins found on the Motherboard
- Process has metal pads
- Easier to dismount CPU
- Widely used by Intel
- Pin Grid Array
- More durable motherboard
- Pins found on the processors
- Motherboard has a socket with tiny holes in them
- Easier to mount CPU
- Widely used by AMD
Also Read: Is a Dual Core Processor Good for Gaming?
Here we reviewed the key differences between LGA vs PGA sockets. Like two opposite sides of a coin, LGA, and PGA sockets couldn’t be more different in their physical form and characteristics.
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. Albeit, it is my personal opinion that LGA is superior in terms of mitigating risks.