corsair vengeance 3000mhz

Hey guys, just a quick one.. Not exactly overclocking but technically it is. I haven't encountered that before. I ve bought a set of 16x2 GB Corsair RGB memory CL15 3000mhz. If i select an xmp profile on my z490 G gaming it sets out unusual values. FSB is set to 102.5 ( which i can understand...

I'm just about to buy some memory for a HTPC build and I'm a little unclear if all of the following will work and what the differences are: Corsair CMK16GX4M2B3000C15 Corsair CMK16GX4M2D3000C16W The ones that have C15 I understand should be marginally better, but these seem to be 3 years old...