Question How do I connect my 3 pin case fans to PSU?

May 18, 2020
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Motherboard - Mini ITX X570 Aorus pro wifi

Case - Lian li TU150

PSU - Seasonic sgx 650

So my noctua uh12a has two PWM fans, I've used the included splitter to plug those into the cpu_fan pin

There is a sys_fan pin but that is being used by a tiny motherboard fan cooling the chipset and nvme.

I have 4 case fans, all noctua and 3 pin (Should have gone 4 pin but alas)

So originally I've bought a molex adapter with a 4 way splitter for my four case fans. I believe my PSU comes with a 6 pin to molex adapter

But now I'm reading that molex is outdated and potentially dangerous.

Link to the adapter i've bought - https://www.ebay.co.uk/itm/4pin-IDE-Molex-to-4-Port-3Pin-4Pin-Cooler-Cooling-Fan-Splitter-Power-Cable/402044017863?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649


However I've been reading about fan hubs and sata connections. They tend to be for PWM fans, and they all require a plug into the motherboard. So I'm not sure if that's right either?

Any help would be appreciated
 
May 18, 2020
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So, following on, maybe having 4 fans constantly at 2000rpm (plus the sound of 2 pwm cpu fans) would actually be too much for a mini itx build.

I've cancelled the 4 noctua a12x25 FLX, and bought 4 noctua a12x25 PWM, along with Noctua's fan controller. That way all fans go into the controller, the controller into the motherboard header and sata to power the noctua fan control. 6 fans and a samsumg 860 evo on one sata wire is another question though.

However my PSU provides 2 sata cables to PSU, so to avoid any panic, i could just put two sata cables in, one for SSD and one for fans
 
Last edited:

Karadjgne

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Yes. But not for amperage reasons. A Sata power is good for upto 4.5A, that's @ 54w. Each fan only pulls @ 3-4w. And the ssd not much more than that. The fans are not sensitive to power fluctuations with stops/starts so will be happily turning throughout, but SSDs are a different story and the controller boards are quite sensitive. Seperating the 2 would be advisable, but not necessarily a must.

No, molex isn't dangerous in the slightest. It's actually stronger at 5A and a lot more robust than the Sata connectors that tend to break after a few years worth of heat cycles. The dangerous part is people insisting that just because a gpu comes with a molex-6pin adapter that they can use ancient, cheaply built and totally crud/underpowered psus that don't have the correct/necessary connectors because they have a molex adapter. 5A = 60w, pcie 6pin = upto 120w possible, 75w standard. That = fire potential.
 
May 18, 2020
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Yes. But not for amperage reasons. A Sata power is good for upto 4.5A, that's @ 54w. Each fan only pulls @ 3-4w. And the ssd not much more than that. The fans are not sensitive to power fluctuations with stops/starts so will be happily turning throughout, but SSDs are a different story and the controller boards are quite sensitive. Seperating the 2 would be advisable, but not necessarily a must.

No, molex isn't dangerous in the slightest. It's actually stronger at 5A and a lot more robust than the Sata connectors that tend to break after a few years worth of heat cycles. The dangerous part is people insisting that just because a gpu comes with a molex-6pin adapter that they can use ancient, cheaply built and totally crud/underpowered psus that don't have the correct/necessary connectors because they have a molex adapter. 5A = 60w, pcie 6pin = upto 120w possible, 75w standard. That = fire potential.

Thanks for your response, very informative.

Source - https://noctua.at/en/nf-a12x25-pwm/specification
Noctua NF-A12 PWM fans
Max. input power - 1,68 W
Max. input current -0,14 A

I have 6 fans, so 10.08w

Samsung 860 EVO - https://www.samsung.com/semiconductor/minisite/ssd/product/consumer/860evo/
POWER CONSUMPTION (IDLE)
Max. 50mW
AVERAGE POWER CONSUMPTION
(System Level)3)


1,000 GB: Average 3.0 W Maximum 4.0 W
plus the 4-5w from the ssd.......yeah, I may separate them if cable management doesn't become swamped. Thank you for your help!
 

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