Depending on the specification of the mixed memory modules, whether the system boots is a coin toss. Even if it boots,the system might throwmemory errorsora blue screenunder specific conditions.
Whether mixing memory modules works mostly depends on their frequency, latency, size, rank, and memory chip used.
If you absolutely need to mix RAM, I suggestchoosing RAMwith close to identical specifications. Meaning, the same frequency, latency, size, rank, and if possible even brands. Even then, thesystem might run into errors.
In this article, I’ve discussed how the system behaves when you mix RAM and whether it is okay to do it.
Mixing RAM With Different Speed and Latency
Technically, you may install memory units with different speed and latency. But whether the system boots is uncertain.
All the memory units installed in a motherboard run at the same frequency.If your system already has slower RAM, there is no point inadding faster RAM.
The faster RAM will also run at a frequency of the slower RAM. Well, that’s for the best-case scenario.
Fewmotherboards and RAMmay not be able to run at a higher speed RAM at a lower frequency. In such a situation, thesystem will not P.O.S.T.
Similar toRAM frequency, its latency also works the same way. Installing memory sticks with differentCAS latenciesmeans thatthe system will use one with a higher delay.
Recently, I added an extra 8GB RAM to my HP laptop with 8GB RAM. The memory speed and latency of the two RAM sticks were not identical. One had a default speed of 2666 MT/s Cas Latency 17 and the other ran at 2400MT/s CL 19.
Once I installed both RAMs, the system got through POST. When I checked the BIOS, the system, by default, ran both memory modules at 2400 MT/s. This was also my CPU (Intel i5 8th Gen)’s max supported RAM speed.
I also installed a 3000 MT/s CL 15 and a 3200 MT/s CL 16 both of 8GB capacity on my ASUS B450 Plus. But in this setup, the system did not even boot into BIOS.
This particular system was not able tolower the speedof the 3200 MT/s module. That’s the reason my system failed to boot. Further, there are also cases where a system with a dedicated GPU showed errors when mixing RAM.
So,you cannot be fully certain that mixing RAM with different frequencies and latency will always work.
