Explaining the Different Types of RAM Slots

Evan Gower July 15, 2019

When you talk about the random access memory (RAM) of your device, you’re actually talking about two parts – your RAM module and your RAM slots. Each slot will fit a certain module to at, which means that certain types of modules just won’t fit.

Explaining the Different Types of RAM Slots

To understand the different types of RAM slots, we need to look at what types of RAM modules exist and how they differ. Once you know that, it will be easy to figure out why RAM slots are also different from one another.

What Is a RAM Slot?

RAM slot, socket, or a memory slot is a gap on your computer’s motherboard where you can insert your RAM. Depending on the motherboard type, there might be up to four memory sockets. If you have a high-tier motherboard, you can even have more.

There are three most common types of RAM:

SDRAM (Synchronous DRAM): A type of memory that synchronizes using the system clock of your computer.
DDR (Double Data Rate): Uses both the rising and falling edge of the clock, which can double the computer’s memory. You’ll find the latest version of the DDR technology on the newest video and memory cards.
DIMM (Dual In-Line Memory Module): This module contains a circuit board and an additional RAM chip. SO-DIMMs are the newest version of the DIMM and are usually part of laptop computers.

What Makes RAM Slots Different?

Throughout the history of RAM, the physical shape of the modules has changed. These physical modifications are what made the modules faster. At the same time, the changes impacted the look of RAM sockets too. Some of the changes include:

A different number of pins – Newer RAM modules have a higher number of pins than the older ones. That is why you can’t insert newer RAM modules into older sockets.
The different gap between pins
Keyway slots are in different locations in the connector space
Different height and length – The length is more problematic since it either fits in the RAM socket or it doesn’t. The height may vary even among the same module types because it doesn’t have to fit anywhere.
Indents and shapes – Newer modules have an indent on their edges so you can take them out easily, and their shape also varies depending on the version.

Different Types of RAM Modules Explained

There are various RAM slots depending on the module. Let’s start from the beginning:

SDRAM: This module had a 64-bit bus and needed 3.3V to work. What’s important is that it had 168 pins DIMM, so the SDRAM slot had 168 empty pin sockets.
DDR1: The first double data rate memory had 184 pins. It was popular from the late 20th century to 2005. Its maximum capacity was 1GB, and it went into the AMD Socket A and 939, Intel Socket 478 and LGA 775, and Socket 756.
DDR2: This module has 240 pins per DIMM and a capacity of up to 4GB. It replaced DDR 1 in 2005 and was popular for a few years. It supported the Intel LGA 775 and the AMD Socket AM2.
DDR3: Physically, this module has a similar shape to its predecessor. It has 240 pins, but a higher frequency range and a capacity of up to 8GB. The RAM sockets that can support it include the LGA 775, 1150, 1151, 1155, 1156, and 2011, as well as the AMD AM1, 3, 3+, FM1, FM2, and FM2+.
DDR4: The fourth generation has 288 pins and can go up to 16GB. It is currently on the high-end of the spectrum and is compatible with the Intel LGA 2011-E3, 1151, and AMD AM4 sockets.

Do RAM Slots Really Matter?

Although the RAM slots are the last thing that comes to your mind when you’re purchasing your computer, it would be good to check that out too. Sometimes a motherboard can be a bit older, meaning that you can’t plug in the latest RAM modules in it.

However, the more important thing you should look at is the capability of your motherboard. If it’s in the mid-tier or low-tier, chances are that the slots will support older versions of RAM modules.

In case you’re unsure if your motherboard will support the RAM module you are buying, you should consult with a tech expert. They will usually be able to tell you exactly which RAM module to get based on the motherboard specifications you give them.