With the recent Intel CPUs I’ve used (my last CPU was the 13900K) I was running RAM in Gear 1.
As for Infinity Fabric - that’s not something you’ll find as a setting in Intel BIOS. If you’re curious about Intel IMC, there’s plenty of information online. But I’d rather not go too deep into that here, since the topic is about 48GB or 64GB RAM.
Interesting. That contradicts everything I’ve read about Intel being able to use Gear 1. But I believe you. I agree that this is off-topic, so I’ll leave it there.