When building a computer you want to make sure all the components are compatible with each other, that way you don’t have any issues.
In an ideal world, you will have the same sized RAM, but everyone’s situation is different and you might only be able to use a 4GB stick of RAM with an 8GB one. For whatever reason this is your situation, then it’s a good thing you clicked on this article.
So, can you use 4GB and 8GB of RAM together?
Combining 4GB and 8GB of RAM is possible, but using different memory sizes could cause a decrease in performance. However, you can lower the performance deficit by using two RAM modules of different sizes, but same clock speeds. In the end, it is recommended to use RAM of the same size if possible.

In this article, we will discuss what RAM is, how you can use 8GB and 4GB of RAM together, and what you should consider before using RAM of two different memory sizes.
What Is RAM?
RAM is short for (Random Access Memory). It is your temporary memory that stores temporary files inside your computer when doing a task. It’s the reason that you can process so many different actions in a game, and the reason why you can keep applications in the background running without having to turn them off completely.
Because RAM is only temporary when your computer is shut off the files stored on your RAM are erased and that is why it takes a little longer to startup applications when you just turn your computer on after a shutdown.
Check out: How Long Does RAM Last?
What To Consider Before Using 4GB and 8GB of RAM Together
If you end up having to use 4GB and 8GB of RAM together for whatever reason there are a few things you need to consider and take in mind before you do so.
You need to consider everything we are about to tell you down below if you want to get the best experience out of using two different RAM sizes, and not waste anything.
Does Your Motherboard Support It?
One thing you have to be sure of is if your motherboard supports using different-sized RAM.
Specifically, with using 4GB and 8GB of RAM some motherboards might not support that because they can’t run on 12GB of RAM.
Most motherboards are built to run on 4GB, 8GB, 16GB, 32GB, etc.
As well as the type of pins and the number of pins your RAM sticks have should be the same.
For compatibility issues, it is best to check your motherboard’s manual to make sure the specifications of your RAM are compatible with it.
I cannot speak for all motherboards because every motherboard is different and has different requirements.
To learn more about this I have another article that goes through how to check if your RAM is compatible with your motherboard.
Is Your RAM The Same Generation?
Next, is to make sure your RAM is of the same generation. You cannot mix DDR3 RAM with DDR4 RAM because they have different architectures that are not compatible and both of them won’t be able to fit in your motherboard.
This goes back to motherboard compatibility because motherboards will only support a specific generation of RAM which will most likely be DDR4, but in some cases, if it is an older motherboard it might support DDR3 or DDR2 as well.

This is very important to keep in mind because for most people the reason why they will have 4GB and 8GB of RAM is that they got one stick from a different PC build which most likely is your old PC or someone else’s.
What Clock Speed Is Your RAM?
You also need to consider the clock speed of your RAM. Let’s say you have a stick of RAM that is 4GB and has a base clock speed of 1333Mhz but then purchase a stick of RAM that is 8GB and has a base clock speed of 2133Mhz.
Your RAM will automatically have to go down to the lowest speed. So, you are wasting the performance advantage of the RAM with 8GB because it is too fast for your 4GB stick.
RAM has to work simultaneously with each other so one can’t be faster than the other or else you will experience a lot of lag and glitching when using your computer.
You should also read: Is Ram or Processor Speed More Important?
Can You Use 2 Sticks of 4GB with 1 8GB RAM Stick?
Yes, you can combine two 4GB RAM modules with one 8GB module as long as you have 4 available memory slots. However, it’s important to ensure that the memory modules are compatible, meaning they should be of the same type (e.g., DDR4) to work together. Keep in mind that the system will run at the speed of the slowest memory module.
You should also keep in mind that this will be a little bit slower than using just 2 8GB sticks of RAM because you will not be able to access dual-channel mode or quad-channel mode because you have 3 sticks of RAM, so your motherboard will work as 3 individual channels.
Conclusion
In conclusion, combining 4GB and 8GB of RAM is possible, but using different memory sizes could cause a decrease in performance.
However, this performance deficit can be lowered by using two RAM modules of different sizes but the same clock speeds.
It is recommended to use RAM of the same size if possible. Before using 4GB and 8GB of RAM together, it is important to consider whether your motherboard supports it if your RAM is the same generation, and what the clock speed of your RAM is.
You also need to ensure that the memory modules are compatible, meaning they should be of the same type (e.g., DDR4) to work together.
While it is possible to combine two 4GB RAM modules with one 8GB module, the system will run at the speed of the slowest memory module, and using just 2 8GB sticks of RAM will provide better performance as they allow for dual-channel or quad-channel mode.