RAM Compatibility for ASROCK Fatal1ty B450 Gaming K4

[Hocigache]

Hello guys i think of buying the ASROCK Fatal1ty B450 Gaming K4 it looks good enough for my budget build and i am willing to start with 2 x 8 GB 2400MHZ of RAM and upgrade for more ram later plus a Ryzen 5 2600X processor and the problem is i dont get the table bellow that i copied from the ASROCK supported ram website page for this motheroard, i dont know if this motherboard will support 4 x 8 GB 2400 MHZ later on.

 

- AMD Ryzen series CPUs (Pinnacle Ridge) support DDR4 3200+(OC) / 2933/2667/2400/2133 ECC & non-ECC, un-buffered memory*

UDIMM Memory Slot				Frequency(MHZ)
A1	A2	B1	B2
-	SR	-	-	2667
-	DR	-	-	2400
-	SR	-	SR	2667
-	DR	-	DR	2400
SR	SR	SR	SR	2133
SR/DR	DR	SR/DR	DR	1866

[Reznik]

If I'm reading that chart correctly, if all 4 DIMMs are populated it'll run single channel and at 2133.   Not sure if that's correct or not.  I've heard it's typical for RAM speeds to go down on Ryzen when you go from 2 to 4 DIMMs.  Maybe that's just offically what it'll run as/support.  I haven't tried to run 4 DIMMs yet on any of my ryzen setups.