Connect Case Fan to Motherboard Header or Power Supply

[jhigh2000]

Are there any disadvantages to connecting a front intake fan to the variable speed motherboard fan header? The MB documentation states that the fan will turn on and run at 70% when the temperature sensor reaches 36C/96.8F and will run at 100% at 46C/114F. It will turn off when the temperature comes down to 31C/88F.

Would it be better to connect the fan to the PS and have it always run at a constant rate? The Enermax has a manual variable speed control and can bet set to run at 1000 - 3000 RPM for the desired cooling/noise ratio.

Thanks in advance.

Brief summary of hardware:

P4 1.9 w/stock retail fan
7200 RMP Maxtor HD
Geforce 4 4400
Linksys NIC

Mid-Tower ATX Case

Exhaust Fan:
Generic 80mm Exhaust fan below 300W PS (also exhaust)

Intake:
Enermax UC-8FAB 80mm

 

[punkrawket]

if you were me i would connect it to the psu

but that's me.... my delta hs fan is on the psu too 😀

 

[Pheran]

Just out of curiousity what motherboard has this variable speed fan capability? Sounds pretty slick to me.

 

[jhigh2000]

It's an Intel D850MV motherboard.

 

[Geoffrey]

I'd connect most fans to the PSU...in fact, I'd only connect the CPU fan to the motherboard. I think its best to have all fans running at a constant speed, unless you buy a special device like the DigitalDoc 5, which just uses a bunch of temperature sensors to shut down the fans you want at whatever temperature you tell them to.

 

[ChrisADuffy]

my vote is for the psu.