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Can You Use 8GB and 4GB RAM Together? (YES! But Be Careful)

Using 4Gb and 8GB RAM together


Can You Use 8GB and 4GB RAM Together?

You can use 8GB RAM and 4GB RAM together, but doing so can affect performance. Although you’ll have a total of 12GB RAM, it will be slower than using two memory sticks of the same size.

When using 8GB and 4GB RAM together, they should have the same voltage rating. Their controllers and motherboard must also be compatible with each other.

  • When 8GB RAM and 4GB RAM are used together, both the RAM sticks will operate at the frequency of the RAM with the lower frequency.
  • In dual channel or flex mode, both RAM sticks will operate in parallel as two 4GB RAMs with optimal performance. The remaining 4GB RAM will operate in single channel mode. In some cases, the whole 12GB RAM will revert to single channel mode.
  • RAM may not work with one of the slots in the motherboard. In this case, swapping the slots may help.
  • The motherboard should be capable of supporting 12GB RAM either as a split dual channel or single channel RAM.
  • The two RAM sticks must be of the same type and have the same number of pins.
  • Although the system will work with 8GB RAM and 4GB RAM most of the time, there may be a few instances where it will not.
  • There may be a compatibility issue between the two RAM sticks.
  • If one of the RAMs becomes faulty, you can continue using your system with the other RAM until you get the defective RAM set right.


Disadvantages of Using Different RAM Sticks

While you can use two different RAM sticks, they pose some disadvantages when compared to using two RAM sticks of the same type.

Some drawbacks users have experienced with two different RAM sticks are the following.

  • The RAM sticks are likely to have different timings, voltages and speeds that affect the overall performance.
  • If they are used in systems with an AMD processor, they will support only single channel operation with 20 percent less gain. On Intel systems, they may support 4GB dual channel and 8GB single channel modes or a single 12GB single channel mode.
  • The system may experience certain problems if you use different RAM sticks from different manufacturers such as related to latency and stress on the memory controller. This can lead to RAM overheating.
  • If you use two RAM sticks of different frequencies and voltages, they will often operate at the frequency of the lower RAM and the voltage of the higher RAM. Thus, the most effective RAM will exhibit the performance of the slowest RAM and deprive you of the benefits of dual channel mode, especially if they are of different brands.
  • The system may have booting problems if the overall RAM capacity, considering the sum of the different RAMs, is not supported by the motherboard.
  • If you use two different capacity RAMs on a dual channel board, they will operate in single channel mode with 25 to 30 percent less bandwidth.


Can I Use 2x4GB RAM and 1x8GB RAM?

You can use 2x4GB RAM and 1x8GB RAM together if the motherboard of the system supports a total of 16GB RAM and an asymmetrical configuration.

There are many instances where users have opted for 2x4GB RAM of one brand and 1x8GB RAM of different brands and have had absolutely no problem while some of them have experienced system instability.

Most present-day systems have an even number of slots for RAM sticks in their motherboard. The slots are usually present as pairs. Thus, if your motherboard has four slots, you can most definitely go about installing just three RAM sticks.

Mixing up different configuration RAM is not recommended in most cases to get the best out of the dual channel or quad channel modes.

The two RAM sticks that are inserted in a pair of slots will operate in dual channel mode. On the other hand, the RAM stick that is fitted in the third slot with its pair slot empty will function in single channel mode.

If you insert the two 4GB sticks in a pair of slots adjacent to each other and the 8GB in a third slot, the 4GB sticks will support dual channel mode and will be slightly faster while the 8GB stick functions slightly slower in single channel mode.

The 2x4GB RAM and 1x8GB RAM sticks tend to show slightly less RAM performance when used together because one of the sticks operates in the single channel mode. However, the system will undoubtedly perform better than when it had just two sticks installed.

Avid gamers may tend to experience a mild performance lag and tend to lose out on a couple of frames per second although this will not affect the overall gaming experience.


Can I Use 2x8GB RAM and 2x4GB RAM?

You can use 2x8GB RAM and 2x4GB RAM together if the motherboard of your system supports their usage. The system will run in compatibility mode.

It’s important to keep in mind the voltage and timing of the RAM sticks. Also, all the RAM sticks will run at the speed of the lowest RAM.

I feel it’s considering opting for this combination if the 2x8GB RAM and 2x4GB RAM have the same speed for the best performance.

You might want to check out if there is any specific slot assignment for the sticks. Some systems recommend that you fit the larger sticks in the first couple of slots followed by the lower RAM sticks in the next two slots.

Motherboards come with an even number of DIMM slots in different colors. If you have a motherboard with four slots, there will be two slots in one color and two of another color.

It’s ideal to use slots of the same color for the same capacity RAM. This means that you’ll have one 4GB RAM and one 8GB RAM in each channel.

It’s recommended that when you use the two pairs, you use pairs bought at the same time as a kit. This will reduce compatibility issues that might be encountered otherwise. Mismatched use might also make it difficult to set the automatic settings.


4GB + 8GB RAM Dual Channel

It’s advised to opt for 4GB RAM and 8GB RAM sticks so that you have 12GB RAM. This is more beneficial than having two 4GB RAMs operate in dual channel mode especially if you are into tasks like content creation. You may consider opting for SSD type RAM for fast performance.

Keep in mind that when you use a 4GB RAM and an 8GB RAM combo, it often supports partial dual channel. 4GB of the 8GB RAM stick will function in dual channel mode along with the existing 4GB stick. The remaining 4GB will operate in single channel mode.

However, this depends on the processor to a large extent. Some processors like Intel may support this while those like AMD are not in favor of mixing up RAM. There are chances that the single channel RAM will be used before the dual channel.

To know the capacity of the current RAM stick in each slot, you can check the sticker with details on it. This will help you decide what capacity memory stick should be put in each slot.

Using a 4GB RAM stick along with an 8GB stick will often cause the overall performance to be marginally lower although it will not make a noticeable difference. Also, a single 8GB RAM is likely to operate slower than a pair of matched 4GB RAM sticks.


How to Mix RAM Sticks

It may be required to mix RAM sticks in some cases instead of using an identically matched pair. There are a few aspects to be borne in mind when you do this to get the best out of the mixing. Some of them are given below.


  1. You can’t mix RAMs of two different types.
  2. You can mix a DDR RAM with a DDR2 RAM or a DDR3 RAM with a DDR4 RAM.
  3. If you’re going to buy a new RAM stick to use along with your existing RAM, buy the same type and model that is currently fitted in the system.
  4. Ensure that all the RAM sticks have the same voltage, timings and CAS latency. These values can be adjusted in the BIOS settings.
  5. When mixing two RAMs of different frequencies, keep in mind that the motherboard will make the RAM stick with the higher frequency clock at the frequency of the lower RAM.

It’s worth remembering that none of the above measures offers the assurance of successful RAM functioning.

You’re likely to see a blue screen on your system if the motherboard isn’t compatible with one of the RAM sticks, or if the RAM sticks are not compatible with each other.



You can use 4GB RAM and 8GB RAM together, but use them with caution. You must understand the risks of mixing the RAM sticks. They must be compatible both with the processor and one another.

The motherboard must support the combined RAM capacity.

This is why RAMs are often sold as a matched kit of 2x4GB, 2x8GB and so on. The pair in a matched kit offers the assurance of working with each other.

Ernie Lo

Ernie Lo is a qualified web designer and web developer. He works as an IT support technician and website manager at Benleigh Vending, and he also fixes vending machines.

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