ASRock AB350M Pro 4 fan splitter advice

[seanobennett]

After some quick help with fan configuration on a new Ryzen build.

Local computer store recently did 15% off when a complete system (of parts) was purchased - which was awesome so I was down there pretty quick. So was everyone else. They'd sold out of a number of parts I was after and I had to make some decisions on the spot (with a line up of people literally out the shop door).
Ended up with the ASRock AB350M Pro4 which at the time I didn't realise only had 3 fan headers (1 X CPU, 1x 4 pin and 1 X 3 pin).

I already had my heart set on Cooler Master Silencio 352, so that and it's two pre-installed fans are all mine. Due to location of PC the front fan is to loud as it is plugged into 3-pin so runs at 100% all the time.

Was thinking of purchasing a Noctua NF S12A PWM as an extra intake fan on the front (top). Now stay with me here.... I am thinking of plugging it into the 3-pin header. "What a waste of a PWM Noctua" I hear you say. Rationale: computer store has them in stock all the time. They should be much quiter and move more air than the Cooler Master XtraFlo pre-installed. I will use the Y-splitter that comes with the Noctua to connect the other 2 fans (I.e. exhaust fan and front intake -bottom). Additionally if the Noctua is still to loud I have option of Low Noise Adpadter (also included). I'm trying to maximise cooling and reduce noise at the same time, which don't always play nice.

Noctua XtraFlo specs are 0.34A, 4.08W.
Will this be an issue on the 4-pin header (which I can't find documentation on but most people are saying 1A)? Have seen people mention something about start-up power draw is always higher.
Is this all a foolish idea? Am I a genius? Why is this post so long? Will this even help noise and/or temp?

Additional specs:
Sapphire RX 580 Nitro+ OC
Ryzen 1600x
Thermaltake Contact Silent 12 CPU cooler
2 x8GB Corsair Vengeance
Corsair CX550M
Samsung 850 Evo M.2
(remember how I said things were sold out... had to change a few parts, CPU, GPU, RAM, while standing at the counter for what was in stock because if one thing was missing = no discount).

Thank you to anyone and everyone for any help/feedback.

 

[CountMike]

Check BIOS to see if there's a PWM > Voltage switch for fan control, most new MBs have that.

 

[seanobennett]

I'd had the thought of voltage controlling the fan but couldn't find a setting easily visible. Poked around in the BIOS until I got lost and out of comfort zone. Any ideas what it might be called/be under?

 

[neiler0847]

I was looking for an mATX B350 board. I'm already a user of the ASRock AB350 Pro4 (full ATX version) and love it, so my first choice was to look at the ASRock AB350M Pro4. The single 4-pin case fan header really discouraged me; I am building a 7-fan system.

But while looking at PWM options, I found this gizmo online...

https://www.amazon.ca/dp/B00VNW556I/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=3APEK6DZBLFRG&coliid=I34UFE1VW33BJX

... wondered if I could use it to control the 7 fans through the one 4-pin header.

Just to be clear, I haven't tried it, but it's still sitting in the back of my mind as a possible solution.

 

[madmatt30]

@neiler0847 - you want a powered one if you're running more than 3 fans from 1 header (I'd consider 3x .25a fans safe , any more is pushing it)

@seanobennett - remove your rear exhaust & fit that as the extra intake , you want a matched pair if fans when running from a single header.

Use the Y cable supplied with the noctua to run those 2 fans to the 4 pin header.

Fit the noctua as exhaust using the lna adapter to the 3 pin header, it still pushes good airflow at 900rpm & is virtually silent.

That's your best way of doing it IMO.

 

[madmatt30]

Your other option is running the 2 intakes with both the splitter & lna adapter inline thus running them at around 800rpm.

Then plugging the noctua (still as rear exhaust) in to the 4 pin directly.

Worth trying , I have no idea if the extra flow fans would be acceptable running at 7v noise wise.

 

[seanobennett]

I like the look of that splitter. It runs off PSU so no worries about header power draw. Would all fans plugged into it have to be the same? And would they all be controlled by the info provided through the 4 pin header, i.e. will all run at same speed?

@madmatt30 - was always thinking of having the two XtraFlo fans running of the Y-splitter. Just one as intake and one as out. Firstly, = less moving of fans (I have banana fingers) and I also thought it might work quite well. Noctua on front at 100% others running at maybe 40% while cool. Extra intake and the exhaust world ramp up as temps in increase.

Edit: was also thinking this method would ensure positive pressure in the case at all times.

 

[neiler0847]

I don't know for sure ... but my suspicion is that all of the fans will need to run at the same speed (or maybe % of max speed). To the motherboard it will look like one fan. So you'll create your custom fan curve in the BIOS, telling it what % of power to run at for each temperature.