I’d definitely take the opportunity to make sure the BIOS is up to date (just to be sure you’re running one that supports the newer CPU), or just default everything if you’re already on the current version before pulling the 5600G and dropping the new one in. Then after you’ve confirmed the board recognizes the 5700X3D it’s just a matter of changing your settings back and dialing in the memory timings.

I know it’s tedious, and probably not strictly necessary, but I figure it’s better to start off with a clean slate whenever you swap out a CPU or reconfigure your memory, just so something you didn’t think about doesn’t come back to bite you later on.

I usually just go through all the BIOS screens where I’ve made changes and take photos with my phone, then use those as cheat sheets to refer back to.

FYI unless you’re planning to manually tune that memory to a lower speed, DDR5@6800 isn’t really feasible on AM5 at the moment. 6000MHz is the current sweet spot, and even getting that stable is much easier to achieve with 2x16GB modules.

Should work fine. You’d just have to set the timings manually to run them all @3200 (one XMP profile runs at 3333MHz, while the other is set to 3200, even though the main timings and voltage appear to match otherwise). Or if you didn’t want to bother with setting everything up manually you could probably run both with the second profile, which is 3000MHz on both kits.

Four sticks is usually harder on the memory controller than two, but you wouldn’t be pushing high clocks on the memory anyway, so you’ll probably be fine. That said, a new 32GB kit would be simpler in the long run, even though it’s cheaper to just add a second kit.