MSI, XMP profile question

[kmd subs]

Hello, first time PC builder here, so I'm pretty new at all this. I haven't actually started the build, so I'm looking to clarify something before I do.

I have this CPU/mobo and RAM
CPU: Intel Core i3-6100 3.7GHz Dual-Core Processor
Motherboard: MSI Z170-A PRO ATX LGA1151 Motherboard
Memory: G.Skill Ripjaws V Series 8GB (2 x 4GB) DDR4-2666 Memory

The mother is going to default the frequency down to 2400 or 2133, is that correct? And if I want to make sure I get the full 2666 performance, I'm going to have to create my own XMP profile and enable it through MSI's BIOS?

Also, should I do this before or after I install the OS? Or does it not really matter at all?

Any feedback is appreciated, thanks.

 

[Suztera]

It will default to 2133.
There should be an XMP profile for your ram once you installed it onto your motherboard. You select it within the BIOS.

You can choose to set it to 2666mhz before or after installing the OS. Ideally you should keep it at default until you tested the build is stable at stock speed as a precaution.

 

[Dark Lord of Tech]

It may or may not run 2666 with the i3 , with a Z board it has a chance if the memory controller can handle it , sometimes more voltage is needed.

 

[kmd subs]

Thanks for the feedback folks.

It may or may not run 2666 with the i3 , with a Z board it has a chance if the memory controller can handle it , sometimes more voltage is needed.

Can you explain? When you say more voltage, are you referring to increasing the voltage in the XMP profile? Also, if turns out my CPU can't handle 2666, will attempting to do so affect anything ... more specifically, break anything?