RAM Choosing Trouble

[Zameer Hussain]

I'm Planning to build a new Ryzen PC. I dont know which Ram to Choose.
I have two mother Board Options
MSI X470 Gaming M7 AC
1866/ 2133/ 2400/ 2667(OC)/ 2933(OC)/ 3200(OC)/ 3600+ Mhz
Gigabyte X470 Aorus Gaming 7 WiFi

DDR4 3600+(O.C.) / 3400(O.C.) / 3333(O.C.) / 3200(O.C.) / 3000(O.C.) / 2933 / 2667 / 2400 / 2133 MHz memory modules
 

This is the Memory Compatibility of the Motherboard.

I want my PC to use 2933 or 3200 Mhz 32 GB Ram.
But i saw somewhere even if i buy 3200Mhz Ram it wont use 3200 Mhz. It Will be only using around 2133 or 2400 Mhz.
Please Help Me out. and Also one thing, The Gigabyte Board has 8+4 Pin CPU power Connecter and MSI has only 8 Pin. I dont know why there is an extra 4 pin on the Gigabyte Board. DO i need to plug in the 4 pin or just leave it?
Help Me out

 

[Mamonos]

It will be working fine you will just need to enable DOCP in the BIOS or eventually set the RAM speed manually.

[Zameer Hussain]

what about extra 4 pin in the Gigabyte board?

 

[DildorTheDecent]

7 minutes ago, Zameer Hussain said:

what about extra 4 pin in the Gigabyte board?

 

The extra 4 pin is additional power for overclocking.

 

Ryzen doesn't go fast or OC high enough to require the additional power. So you can do without it.

[Mamonos]

Just leave it unplugged, the standard 8pin connector will be just fine.

My guess is that the additional 4 pin is there to supply extra power for extreme overclocking but I am not sure about that.

[Zameer Hussain]

i dont want to overclock my CPU. I want a crash free system. So should i leave the 4 pin unplugged or plug it?