xeathkid

Hello. I have same speed on g - 64gb with msi unity without a problem so far.

You should be fine

You don’t need z790 for 12.9k. 690 is fine.

Also I’m using 6400 on my 12900k

It depends on the speed? If I recall. Unless you tweak but it’s still a problem

I’ll say wait it out until 15th gen.