Question ASRock X570 Phantom Gaming 4 RAM

reukiodo

Honorable
Jun 1, 2014
3
0
10,510
I have my build here: https://pcpartpicker.com/user/reukiodo/saved/gwWhkL except for the 5600X wasn't available so is substituted with a 3600X (for now)

key components:
ASRock X570 Phantom Gaming 4
AMD Ryzen 5 3600X
G.Skill Ripjaws 5 - https://www.gskill.com/product/165/184/1571733123/F4-2666C18D-64GVK

Reading the manual and specs https://www.asrock.com/mb/AMD/X570 Phantom Gaming 4/index.asp#Specification it makes me believe that the 2 RAM sticks should be installed in A2 and B2, however, the board will only boot with both when they are installed in A1 and A2.

I know both ram sticks work well, as they will work independently solo in any slot except B2.

For instance, let's say R1 is the first ram stick and R2 is the second, then these combinations do NOT work for me:
A1 A2 B1 B2
R1 x R2 x
R1 x x R2
x R1 R2 x
x R1 x R2
x x R1 R2
R2 x R1 x
R2 x x R1
x R2 R1 x
x R2 x R1
x x R2 R1

where these combinations work:
R1 x x x
x R1 x x
R2 x x x
x R2 x x
R1 R2 x x
R2 R1 x x

Am I reading the documentation incorrectly, or is there something wrong with my board/ram ?