Is there a compatibility problem with these RAM modules at different speeds?

Question

I'm planning to update some components on my PC and I want to know if I can buy two more modules of RAM without compatibility issues.

This is the new motherboard I will be buying, a Gigabyte B365M-DS3H. It has 4 slots for RAM; now, I only have 2 on my Gigabyte GA-H110M-S2H.

I want to buy the two remaining RAM modules and go for the 32GB of RAM (8GB x4) because sometimes 16GB is small for my work. Currently I have two HyperX Fury DDR4 2133 C14 8GB (CPU-Z says: DDR4-2134, Part number KHX2133C14D4/8GB) and I'm wondering if I could buy a pack of two of any of these newer models:

• Kingston HyperX Fury Black DDR4 2400Mhz PC-19200 2x8GB CL15
• Kingston HyperX Fury Black DDR4 2666Mhz PC-21300 2x8GB CL16
• Kingston HyperX Fury Black DDR4 3200Mhz PC-25600 2x8GB CL16 (Too fast for the motherboard?)
• Kingston HyperX Fury Black DDR4 3466Mhz PC-27700 2x8GB CL16 (Too fast for the motherboard?)

My concern is that even though the new motherboard supports 2666/2400/2133 MHz, my older RAM runs at 2133MHz and it will be different compared to the new RAM.

Is this a compatibility problem ?.

Answer 1

Since you can not overclock memory on Intels current "Bxxx" motherboards, no matter which memory you buy, it will run at DDR4-2133, the slowest common denominator.

I would not expect any compatibility issues with these low memory frequencies.
It may be possible to overclock to DDR4-2666, but you can't really know until you tried. I would not count on that.

Edit: by the way, there is no "too fast" for memory. All higher end memory can be run at lower frequencies. It's just a waste of money.