Your Laptop Memory (RAM) Buyer's Guide

Laptops are limited in the amount of memory that can be installed in them. Access to that memory may also be difficult, depending on the architecture, which limits plans for a future upgrade. In fact, some systems come with a fixed amount of memory that cannot be changed or upgraded.

How Much Memory Is Enough?

To determine if your computer has enough memory, look at the minimum and recommended requirements of the software you intend to run. Your computer should have more RAM than the highest minimum and at least as much as the highest recommended amount.

Also, consider your computer's operating system. Some operating systems use more memory than others. For instance, a Chromebook running Chrome OS runs smoothly on 2 GB of memory because it is highly optimized, but it can certainly benefit from having 4 GB.

Many laptops use integrated graphics controllers that require a portion of the system RAM for the graphics. This reduces the amount of available system RAM by 64 MB to as much as 1 GB, depending on the graphics controller. If the system uses an integrated graphics controller, consider a step up in RAM to account for this usage.

Types of Memory

Memory technology changes regularly as computer architectures advance. Faster CPUs require faster memory with bigger bandwidths. The speed of memory has an impact on the system's performance. When comparing laptops, check both pieces of information to determine how they may impact performance.

There are two ways that memory speeds are designated. The first is by the memory type and its clock rating, such as DDR3 1333MHz. The other method is by listing the type along with the bandwidth. The same DDR3 1333MHz memory would be listed as PC3-10600 memory. Below is a listing in order of fastest to slowest memory types for DDR3 and DDR4 formats:

• DDR4 3200 / PC4-25600
• DDR4 2666 / PC4-21300
• DDR4 2133 / PC4-17000
• DDR3 1600 / PC3-12800
• DDR3 1333 / PC3-10600
• DDR3 1066 / PC3-8500
• DDR3 800 / PC3-6400

It is easy to determine the bandwidth or the clock speed if the memory only lists one of these values:

• If you have the clock speed, multiply it by 8.
• If you have the bandwidth, divide that value by 8.

Laptop Memory Limitations

Laptops generally have two slots available for memory modules, compared to four or more in desktop systems. As such, they are limited in the amount of memory that can be installed. Some brands and models of laptops, such as ultraportable styles, have a fixed memory size that cannot be upgraded.

A laptop requires a specific type of memory, such as one of those in the list above. If your laptop is designed to use DDR3 memory, for example, you can't use DDR4 memory and expect it to perform. The same is true for the speed and bandwidth requirements of the system; determine the proper memory type your system accepts before purchasing a memory upgrade.

Also, a computer has a maximum amount of RAM it can accept that is not based on the physical number of slots. For example, you may be able to purchase two 16 GB memory modules, but that 32 GB total may be over the maximum allowed by your system.

All these limitations are listed in the specifications of any laptop, so be sure to take note of them.

What to Consider When Shopping

First, find out what the maximum possible memory of the system is. This is listed by most manufacturers and indicates the upgrade potential of the system.

Next, look at the memory configuration. For example, a laptop that has 8 GB of memory can be configured as either a single 8 GB module or two 4 GB modules. A system configured with a single memory module has a second memory slot open, one that can be used to expand the amount of RAM in the future by adding a second memory module.

Upgrading memory in a system with both memory slots filled with memory modules comes with a few additional considerations. In a laptop with two 4 GB modules (totaling 8 GB of system memory), one module will need to be replaced with a larger capacity module.

For example, replacing one of the 4 GB modules with a new 8 GB module would give a total of 12 GB (the new 8 GB module and the original 4 GB module). However, it is better to upgrade both 4 GB memory modules at the same time to ensure the fastest performance. Memory modules are usually paired to work with each other in a dual-channel mode and having two modules of differing capacities will not work as efficiently as would a matched pair.

Installing Memory Yourself

Many laptops have a small panel on the underside of the system that provides access to its memory module slots. On other systems, the bottom cover may need to be removed to access the memory modules. In these cases, it is possible to purchase a memory upgrade and install it yourself without much trouble.

If a system doesn't have an access panel or other means to get inside the computer, the memory, most likely, cannot be upgraded. In these cases, the laptop may be opened by an authorized technician with specialized tools to upgrade the memory. Of course, this comes with additional costs.