We choose to overclock by installing 1.35V for the CPU and seeing how high it can go before not being able to complete a Blender run. 5,100MHz is 300MHz higher than what the chip does at stock, which shows that Intel is playing quite close to the wire from the get go.
Corsair provided us with some super-fast Vengeance LPX 4,800 CL18 memory with which to test the board and chip's ability to scale to higher RAM frequencies. We run the test by keeping the XMP settings the same - 18-24-24-46 at 1.5V - and seeing where it maxes out. The MPG Z490 Gaming Carbon WiFi is not able to run them at the stated speeds; topping out at 4,600MHz instead.
That said, an exhaustive list of approved memory shows that multiple kits are ratified at 4,800MHz for this board. We're in the process of obtaining a suitable kit and testing the compatibility ourselves. Stay tuned for an update.
The final Cinebench score is a combination of maximum stable frequency for CPU and RAM. AMD clearly has the upper hand here.