Motherboard Rear Chassis Fan Connector

[_Martin]

Hi,

I'm currently looking to install a second fan onto the motherboards rear chassis fan connector on my Z2 G9 Tower using a Noctua Y-Splitter as opposed to a SATA to 4-pin as it runs the fan at 100% without any control and sounds like a fighter jet beside me because of it. The Y-Splitter would control both the rear chassis fan and PCI-E bracket fan in parallel however with the current draw of the rear fan at 1.2A at max and the additional blower fan at 0.88A at max I'm worried that this could damage the motherboard if I try and draw too much wattage from it.

Does anyone have any info regarding the maximum current the rear fan header can supply as the quickspecs for the tower don't have any information on this matter?

Thanks!

[NonSequitur777]

@_Martin,

Welcome to our peer-to-peer HP Community Forum!

My understanding is that preferably, you should stay below 2 amps.  On the other hand, I have been using multiple dual and triple cooling fan splitter cables for a long time on multiple HP desktop platforms -some drawing well above 2 amps, and haven't seen any issues.  Yet.

Kind Regards,

NonSequitur777

[_Martin]

Thanks for the welcome and reply NonSequitur777. I may like you suggest run with the splitter and take the chance as it would only be running at a max of 2.08A, however, I have also researched that a fan controller could work by taking the motherboards PWM signal and using power instead from a SATA connector therefore drawing no current from the motherboards fan connector removing the risk. This could work but the HP bios is sensitive to missing fans throwing an error on boot but could be worth the punt if the fan controller talks to the motherboard like a single fan would, otherwise the blower fan would have to be manually controlled.

I'm attempting to fit the PCI-E blower fan from the Z2 G4 tower as tomorrow my RTX 3080 arrives in the post which would benefit from more cooling than the standard twin front intakes and rear exhaust. It was mechanically a simple modification as I just swapped the fan assembly between the G4 bracket and G9 bracket as there is minor differences between the two that otherwise wouldn't allow the G4 bracket to fit.

I have just now noticed that HP uses a propriety 4-pin fan connector which I first mistook for a standard PWM 4-pin connector as the raised plastic locating lugs protrude at the outer most ends of the connector compared to the standard arrangement of one at the end and one between the two pins at the other end. Should be simple enough to overcome by trimming one of the lugs off the splitter connector that joins to the motherboard so that it can be properly fitted.