Best memory for 2990wx

###Build Help/Ready:

Have you read the sidebar and rules? (Please do)

Yes

What is your intended use for this build? The more details the better.

Gaming mostly, some workstation uses.

If gaming, what kind of performance are you looking for? (Screen resolution, framerate, game settings)

120+ FPS

What is your budget (ballpark is okay)?

Not mine, for a buddy. Assume budget is not an issue.

In what country are you purchasing your parts?

USA

Post a draft of your potential build here (specific parts please). Consider formatting your parts list. Don't ask to be spoonfed a build (read the rules!).

2990WX, MSI TR40X Pro Wifi

Provide any additional details you wish below.

A buddy has already purchased the MB and CPU. I was talking with him and he is only running 2133 RAM. I know that Zen+ in particular enjoys faster memory and that the Infinity Fabric runs at the speed of the RAM. However, I do not know the max IF speed to target for a 1:1 ratio for best results. My gut thinks 3600 C16 in a 4x8 or 4x16 config but I want to be sure that this will run.

Yes I know Threadripper is not the first recommendation for gaming. This was purchased before my involvement and I just want to help him get the most out of it. I have googled but have not been able top find the max IF speed of this chip.