Matching memory - a curiosity question

[cgilley]

So the other day I'm buying ram to beef up my development laptop. As an EE, it is obvious to me why you want to have matched pairs of RAM. Devices with different characteristics is an invitation to frustration.

That said, it occurred to me that I've never read if pairs of memory modules need to be matched. For example, my laptop has 4 memory slots. The first two slots have 16GB modules for a total of 32 GB. So, I go buy a pair of RAM modules for the other two slots. Do they have to match the first pair?

 

[Calvin7]

Memory is guaranteed in the form sold. Other combinations you happen to make have no guarantee to be compatible together.

Since nothing is stopping you from making such combinations, you will need to do you own compatibility testing with no guarantees.