The Compatibility of Multi-channel when Installing RAM Modules

Last Updated on December 22, 2022

Commonly, PCs and laptops have more than 1 random-access memory (RAM) slot. This may enable multi-channel features, which will significantly increase RAM performance. Then, maybe some of you are new to computers. And have questions like: is it possible to use different brands? Can I use a different RAM capacity? and maybe some other things related to RAM slots. Let’s discuss them one by one.

Multi-channel

Multi-channel is a feature when the computer accesses several RAM modules simultaneously. Common terms in multi-channel are single-, dual-, triple-, and quad-channel ​[1], [2]​.

Simply put, if you just install a RAM module, then the computer will work in single-channel mode. Then, if you install 2 RAM modules, then the computer will work in dual-channel mode ​[1]​.

Commonly, laptops only have a maximum of 2 RAM slots. So the laptop can work in a single- or dual-channel mode according to the number of RAM modules installed. On the other hand, PCs generally have 4 (or more) RAM slots that allow for triple- and quad-channel features ​[3]​. The triple-channel feature requires 3 RAM modules and the quad-channel feature requires 4 RAM modules.

However, not all motherboards support these triple- and quad-channel features. As a result, the installation of 3 RAM modules makes the computer use 2 RAM modules in dual-channel mode, and the remaining 1 RAM module in single-channel mode. Alternatively, installing 4 RAM modules keeps the computer in dual-channel mode on every 2 RAM modules.

Flex mode

Flex mode is when the computer works on dual-channel and single-channel simultaneously ​[2]​. This is common when using two RAM modules with different capacities. For example, installing a 4GB RAM module and a 16GB RAM module in a computer. As a result, both RAM modules will work in dual-channel mode with a capacity of 2 x 4GB, or a total of 8GB. Then, the remaining 12GB on the 16GB RAM module will work in single-channel mode.

Knowing the number of RAM slots

Before buying RAM modules or increasing the capacity of your computer’s RAM, it’s a good idea to know the type and number of RAM slots in your computer, as follows ​[3], [4]​:

• use software such as CPU-Z, HWINFO, or AIDA64 to find out the detailed computer specifications, including RAM; or
• disassemble the PC or laptop case; In this way, you can immediately see the number of slots and the type of RAM on your computer, physically.
• Meanwhile, we can see the RAM capacity and used slots, directly through the operating system. However, you may not find the type of RAM used.
  • Win 10: Press CTRL+ALT+Del, then select Task Manager, select the Performance tab, then click Memory.
  • Mac: open the About This Mac menu and click More Information.
  • Linux: open the terminal by pressing CTRL+ALT+T, type sudo dmidecode -t 17, then press Enter.

RAM module compatibility

When installing several RAM modules, we need to pay attention to several things. The most important things are the type of DDR generation (e.g. DDR3 or DDR4) and its form factor (e.g. DIMM for PC and SO-DIMM for laptop) ​[5]​. Because, a motherboard has only been designed to use one type of RAM. For example, a particular laptop has been designed to use RAM modules with the SO-DIMM DDR4 type.

Other than that, all RAM modules in a computer should have the same specification and brand. These specifications include its frequency/speed, latency, capacity, voltage, and so on ​[6]​. Although the probability is very small, the difference in specifications may raise some compatibility issues such as ​[3]​:

• the multi-channel feature doesn’t work;
• speed and latency of RAM modules decreased, according to the RAM module with the lowest speed and latency; and/or
• level of stability decreased, which may cause a crash, error, blue screen, or not booting at all.

Someone may buy a RAM module according to his financial capabilities. However, many of them plan to increase capacity by adding RAM modules in the future. To avoid various problems that might occur, purchasing RAM modules with the same brand and specifications is highly recommended. On the other hand, we recommend that you save and buy a RAM module kit, instead.

RAM kit

To increase the durability and stability of multi-channel, the memory/RAM kits were created. Commonly, RAM kits are marked with the term n x capacity of each module and are sold in one package. For example, a set of 2 x 4GB RAM kits means that in this RAM kit package, you will get 2 RAM modules with a capacity of 4GB in each module. With a total capacity of 8GB, these two modules can work in dual-channel mode.

RAM kits have the following benefits ​[1], [3], [7]​:

• RAM kits are generally sold at less expensive prices. However, some brands may sell them at a higher price than the non-kit modules.
• Guaranteed compatibility for using modules with the same specifications, from design, speed, latency, capacity, and so on.
• Manufacturers have tested the RAM kits to be able to work in sync with each other.
• Some manufacturers may offer a “multi-channel” warranty, whereas you will not get it if you buy the RAM modules individually.

Frequently Asked Questions

References

Cover image by Marco Verch Professional Photographer on Flickr