Can I upgrade a 16GB Ram slot to an 8GB Ram?

I have a laptop with 8GB Ram but I want more and would like to add a 16GB Ram slot. Can I do it without problems or do two go the same way or is the brand important?

Clock rate and latency are important. Also whether the mainboard has any additional slots.

Ok good to know is it bad if my ram has 2667mhz and the bought 2666mhz does it depend on the 1mhz? And he has 2 thanks.

It is best if you have two of the same because of dual channel. Then it slips even faster.

But whether you can use 32GB RAM, you have to look in the manual for the notebook. Which notebook do you have?

32GB because if you have 2 slots and want to insert 16GB and 8GB, this means that at least 32GB would have to go from the manufacturer, because otherwise it would not accept 16GB RAM.

Look at the manufacturer and also in the firmware updates for BIOS / UEFI.

No, the second clocks just like the lower one. Then you just switch in the BIOS.

Clock rate doesn't matter. That always adapts to the lowest.

OK thank you.

Clear recommendation from me, either you buy the same thing again, or you buy a brand new 16 GB kit. Of course, a clear recommendation can only follow if you know your system. Mainly motherboard and CPU.

Otherwise I can tell you from my experience if you do not buy the identical Ram, approx. 60% works and approx. 40% does not. What you have to say is that high-end boards are more likely to work.