System Fan headers not recognized

[grim night]

Hello, I have a B450 tomahawk max, I looked at my fan curves and noticed that the board is only recognizing System Fan 1 header and not System 3-4 (Which I have 4-pin splitters connected to)

System Fan 1 header has a 4-pin 2 way splitter, while the other 2 are 4 way splitters. All 3 splitters have 3-pin fans connected, Why would the board only be recognizing 1 of the headers?

FYI, the fans connected to all of the headers are powered and work, the only issue is that I can not control Sys 3-4

[stray grove]

Could save a lot of trouble if you just got a powered fan hub. How many fans total do you have?

[grim night]

Hi, I have 3 exhaust (2 top, 1 rear), 2 intake and 3 CPU.

Rear - Sys 1

Top - Sys 3 (splitter)

Intake - Sys 4 (splitter)

I’ll add that it looks like the splitter I had on was the issue, it wasn’t being recognized but I used another one I had and it shows now

What benefits do I get from a powered fan hub? I’m assuming I wouldn’t be able to control them separately if they are all on the same powered hub

[stray grove]

Generally it's just easier as you only have one header to worry about. Generally other than your CPU fans (either on the rad of an AIO or on a air cooler which would should be in your CPU fan header) most people don't care if their chassis fans run at the same speed. Especially since you don't have PWM fans. But that's up to you.

[grim night]

Yeah, so the CPU fans are not an issue because they are on their own header.

Ideally I would like to control the Exhaust and Intake separately to balance airflow (Which Ive had no issue with but its nice to do)