I just build a new HTPC
Silverstone Grandia GD07 HTPC Case3x Silverstone 120mm / 1,200 rpm / 12 V / 0.33A 3 pin fans
(Honghua HA1225L 12SA-Z)
GA-Z68XP-UD4 Motherboard / Intel I3-2100 w. stock coolerThe motherboard has 4 fan headers, but only the CPU header + the SYS2 header have fan speed control, the others run at a constant 12 volts.Using the 12V headers the case fans run ~ 1300rpm and are too noisy.SPCR Fan Noise Results
for same fan in TJ-04E Case 7V 12-16dB, 9V 15-20dB, 12V 23-25dB
If I use the variable speed header the fan is sufficiently quiet for me in the range of 550-950 rpmWould it be safe to run the 3 fans off the single SYS2 header using a 3 way split cable?
I'd prefer to run all 3 fans off the SYS2 header so I can set a quiet slow speed in speedfan and have them only increase if the case gets too hot.
The other alternative is to use a Molex -> 7Volt adapter for 2 fans with the 3rd running on the SYS2 header or a speed controller for 2 with the 3rd one SYS2.
However I'd prefer to have the HTPC automatically control all the fans.
The 3 way splitter cable is the tidiest option and the cheapest at only $2.95 incl P&P