ASRock Z390 Phantom Gaming X - which ATX12v should I use?

Megahertz said:

But he wrote it has only 8 pin connector. So he should plug in the PS 8 pin connector on the MB 8 pin connector.

Agree.

Okay, thank you for all your answers. I'm glad that I'm not the only one not to see this clear.
I can understand that when I have an 8 pin cord from the PSU, that I should use that in the 8 pin socket. BUT ... why then write
"Please connect an ATX 12V Power supply to this connector" for the 4 pin connector? When I get the mobo I'll try it out, and I'll return to this thread and write what is right

Burgurne said:

BUT ... why then write
"Please connect an ATX 12V Power supply to this connector" for the 4 pin connector? When I get the mobo I'll try it out, and I'll return to this thread and write what is right

Honestly if you have such questions you could call Asrock's tech support as they (should) know this board better than us.

Again, my guess is depending on CPU used and power needs is probably why they have two EPS connectors on some of these boards. As I said, mine has two 8-pin connectors. I'd guess the minimum would be the 4-pin connector for a low powered CPU, and probably both connectors for an overclocked CPU like say a i9-9900K (which is what I have).

Edit these two threads confirm my guess...

• CPU power connectors
• 390 Boards: 8+4 Pin ATX?

Yes, I know I don't need both connectors (4 pin and 8 pin), but the manual is not clear about which one to use if ONLY one of them can be connected. Hence my confusion in #0 and as seen clearly in #12. I mean, if I connect an 8 pin in the 8 pin connector, why does the manual then write Please connect an ATX 12V Power supply to this connector ​for the 4 pin socket?

Burgurne said:

...why does the manual then write Please connect an ATX 12V Power supply to this connector ​for the 4 pin socket?

I thought we answered this a few times. Anyway the way I read that statement is "you'll need at least the 4-pin connector" to power the CPU. In other words you need to connect something to one of those connectors or else the CPU won't be powered.

If you don't feel comfortable with that answer perhaps Asrock's tech support may provide a more suitable one.