Laptop RAM vs Desktop RAM

The Random Access Memory (RAM), also known as system memory or main memory, is computer storage that temporarily stores files and software currently being used by the computer. In this guide, we are going to discuss laptop RAM vs desktop RAM to help you make an educated decision when buying one for yourself.

Laptop RAM Vs Desktop RAM: General Overview

We are going to look more deeply into how desktop RAM and laptop RAM compare to each other. Before that, let’s quickly go through each of these system memories.

Laptop on table

Desktop RAM (DIMM)

Desktops use a system memory known as the Dual In-Line Memory Module (DIMM). This is a type of computer memory that contains several RAM chips on a single circuit board. This makes it capable of fast data transfer compared to other types of memories. The memory which is natively 64 bits contains pins that connect it directly to the motherboard.

DIMM is slowly replacing SIMM (single in-line memory module) which uses a 32-bit memory path. Since Dual in-line Memory uses a 64-bit bus, it can afford double the data transfer at once.

This makes them more compatible with the majority of modern computers that pack a 64-bit data width. To achieve the same speed of data rate with a SIM module, you would have to install it in pairs which take up more space on the motherboard.

DIMM is categorized as a dynamic RAM (DRAM). Dynamic means that the memory has to be refreshed constantly, for it not to lose its contents. DRAM is the most common type of primary memory and less expensive than Static memory.

There are several types of DIMMs. These include

  • SDRAM (Synchronous Dynamic RAM)
  • DDR SDRAM (Double Data Rate Synchronous DRAM)
  • DDR2-SDRAM (Double Data Rate 2 Synchronous RAM)
  • DDR3-SDRAM (Double Data Rate 3 Synchronous RAM)

Laptop RAM (SO-DIMM)

Laptops use a type of RAM known as Small outline dual in-line memory module (SO-DIMM). It is much smaller than regular DIMMs and it uses integrated circuits.

SO-DIMMs are mostly in laptops and notebooks that use Mini-ITX motherboards since they have limited expansion space. They can also be in networking hardware like routers and high-end office printers.

SO-DIMMs specifically address common problems laptop builders faced. Since most laptops need to be small and portable by design, big RAM chips like DIMM wouldn’t be ideal since they are large and may not fit into the overall design of the laptop. Using large memory chips like DIMMs would significantly increase the laptop’s size making them unbearably bulky.

A SO-DIMM chip is roughly half the size of a regular DIMM making them more flexible when designing the laptop’s memory slots. They are also pretty easy to upgrade since they are located on an easily accessible area on the laptop’s motherboard.


The first designs of SO-DIMMs managed only 32-bit data bit data transfers and had 72 pins. The pins are the connectors used to attach the chip to the motherboard. However, modern SO-DIMM chips can come with 144 pins and can accommodate the same 64-bit data transfer as regular DIMMs.

Below are some common types of SO-DIMMs:

  • SDR DRAM: has 100 pins with two notches
  • SDR SDRAM: has 144 pins with a single notch
  • DDR/DDR2 SDRAM: has 200 pins with a single notch
  • DDR3 SDRAM: has 204 pins with a single notch
  • DDR4 SDRAM: has 260 pins with a single notch
  • UniDIMM: has 260 pins with a single notch

Laptop RAM Vs Desktop RAM

Random Access Memory is a short-term storage location in your computer that helps in the day to day running of processes. Different types of RAM provide different speeds and are compatible with specific systems. 

Similarities between Laptop RAM and Desktop RAM

Older Versions Of Laptop RAM Are Compatible With Older Models Of Desktops

Perhaps you may wonder if the two types of memories are compatible with each other in case you decide to swap. Well, a very old laptop and desktop memory may swap back and forth.

The number of pins on the RAM memory must be compatible with the slot on the motherboard. After the successful transfer of a laptop RAM to a desktop, the speeds and transfer rates remain the same. 

The only condition required for the two memories to swap is for the RAM to meet the entire specifications match. If the desktop uses DDR3 and you intend to use a laptop DDR3 then it is vital to ensure it meets all the specification needs of the desktop.

Speed is another key factor for the two to be compatible. To determine the speed requirement of a computer system, look upon the motherboard or use a scanner. 

Both Cannot Be Expanded More Than The Capacity Of The Motherboard

Expanding a laptop memory is a common thing for most people especially those who love gaming and designing on computers. It is possible to expand your RAM space on either a laptop or a computer system. 

Some computers come with an extra slot for expandability while others only allow one slot. Those with one slot can only be replaced with bigger memory. However, for you to expand your computer RAM, the motherboard must be compatible with the new memory. 

For example, if the motherboard allows up to 4 GB of RAM you cannot expand your computer to an 8 GB RAM. This rule applies to both laptops and desktops. 

Laptop RAM

Differences Between A Laptop RAM And Desktop RAM

The major differences between the two types of memories can be seen in its form factor. These differences include the following:

Laptop RAM Is Smaller In Size Than Desktop RAM

The main differences between laptop RAM and desktop RAM are seen in its form factor. That is basically the physical size and its pin configuration. A desktop RAM measures about 100, 168, and 184. The total number of pins is 240 pins. The length of the RAM is about 4.5 inches.

On the other hand, a laptop RAM measures 72, 100, and 104. This brings the total number of pins on the laptop to about 204 pins. The average measurement of the laptop RAM is 3 inches. Therefore, this means that a laptop RAM is much smaller than desktop RAM.

Newer Versions Of Laptop Memories Are Incompatible With Desktops

The general rule for making RAM for computers is that the shorter RAM modules are designed for laptops while the bigger RAM modules are for desktop computers. The two are not interchangeable meaning you cannot use a laptop RAM on a desktop RAM slot. 

However, there are some desktop adapters that allow you to use laptop RAM. Before doing this, you should guide yourself by the form factor, meaning the number of pins on the RAM should match the holes on the computer slot. 

Nevertheless, it is important to state that older generations of RAM are incompatible with newer versions. This is due to the RAM not catching up with the modern-day processor speeds. More so, the RAM sticks will not physically attach to the slots on the machine that has a different generation of RAM sticks.

The best way to find out if your laptop or desktop computer system is compatible with the RAM is by looking at the sticker on the RAM stick. You can then proceed to search for SDRAM, DDR, DDR2, or DDR3. 

Another reason why the two memories are completely incompatible is that a desktop memory uses DIMM. DIMM stands for dual inline memory modules of DIMM known as SO- DIMM. SO- DIMM stands for small outline dual inline memory modules.

Desktop RAM

Most laptop memories support other memory types such as SDRAM and almost all forms of DDR. Basically, DIMM modules on the desktop use 240 pins, and the RAM modules have to be plugged on the desktop motherboard. On the other hand, the SO- DIMM laptop memory uses around 240 pins.

Desktops Have Two, Four Or Even Eight Memory Slots While Laptops Have Only Two

Most desktops have more expandability options than laptops. You can add more than two slots or RAM memory on your desktop. On the other hand, laptops come with only two slots which cannot be expanded further. This can be limiting in case one intends to expand its laptop memory.

Desktop RAM Has A Larger Bios Support Than Laptop RAM

Laptop computers can support up to 16 GB while you can expand desktops RAM even more. When it comes to the maximum RAM supported by the operating system, laptops lag even further behind. 32- bit windows support up to 4GB RAM in laptop systems. In desktops, it can go up to 8 GB RAM. 

Main Distinguishing Factor

The main thing that stands out between a laptop RAM and a desktop RAM is the form factor. The difference is seen in the size of the two memories and the number of pins. Conventionally, a laptop RAM is intentionally made smaller than that of desktops. This is due to the size of the laptop. 

Another major difference is in the number of pins. A laptop RAM comes with 204 pins while a desktop RAM has 240 pins. Most modern-day computer systems are adapting to this trend thus swapping the two memories is made impossible.

Desktops have more expansion slots than laptops. Some desktop computers can have up to eight slots for memory input. On the other hand, laptops have only two expansion slots. However, it’s impossible to expand your computer memory more than the capability of its motherboard. 

It is important to note that only old models of desktop RAM are compatible with older models of laptop RAM. For this to happen, the number of pins on the RAM must be compatible with the slot on the motherboard. Swapping the memory will not affect the performance of the computer system. 

When To Use Laptop Memory

Below are some of the instances where you may opt to use a laptop RAM than Desktop RAM:

Desktop monitors on table

When To Use A Desktop RAM

  • If you are a gamer and would like to expand your computer memory to meet your gaming needs
  • If you are a programmer or graphic designer and need to expand your memory further
  • If you always work indoors and do not need to carry your computer outdoor
  • If you need to always upgrade your desktop system to more than two RAM slots

Final Verdict

Laptop RAM and desktop RAM serve the same purpose on the computer. They are both responsible for short term storage of memory in the computer system. It is important to know the computer requirements before buying any type of memory. 

The two memories are highly dependent on the motherboard requirements of the computer. For example, if the motherboard allows up to 4 GB RAM you cannot expand to an 8 GB RAM. Another important guide when buying any memory is the number of pins on the memory stick. 

Always look for a sticker on the RAM to know the number of pins and the category of the RAM stick. Laptop RAM has only 204 pins while a desktop RAM has 240 pins. Also, look for other specifications on the motherboard to ensure the RAM meets the requirements of the computer system. Some of the aspects to look out for include the operating system, the BIOS, and the speed.

In conclusion, we can say that both laptop RAM and desktop RAM work almost the same way in the computer system. If you intend to use a computer outdoors then it is best advisable for you to buy a laptop RAM. This applies to students, tourists, and other travelers.

For those who love gaming, programming, and staying indoors, then buying a desktop RAM can be the better option for them. more so, a desktop has more expandability capabilities than a laptop computer.

Liam Weissman

A lover of MacBook Air and the Dell XPS line of laptops, Liam has been researching and writing as a guest blogger for numerous websites for over 10 years. Now, he blogs about tech trends, PCs, laptops, gadgets, and other emerging gadgets on

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