If the motherboard supports RAM with a frequency of up to 1800 MHz, is it possible to add another one of the same to the existing RAM chip at (1333 MHz)?

Question

RAM

If the motherboard supports RAM with a frequency of up to 1800 MHz, is it possible to add another one of the same to the existing RAM chip at (1333 MHz)?
I got the impression that the frequency of the dice is summed up and my motherboard will not be able to support two at 1333 MHz, is that not so?

Answer 1

1) you can
2) nothing is cumulative
you can even put 1800 and it will run at 1333

Answer 2

In the general case, it is possible, but I strongly recommend reading the list of supported memory on the manufacturer's website, there was a time, interesting surprises happened.
1333 is, as it were, the minimum acceptable standard (for dd3), i.e. almost any memory will work with it, so if you want to raise the frequencies, ...