my cpu fan is connected on system fan port and my cpu fan port is empty.... no issues till now, no warnings...my overall computer running cool with single fan .but is it wrong or cause bad to cpu.everyone say the draw different speeds.i am noobie
by the way my cpu fan with heat sync have 4 wires which is connected in a system fan port
here is the whole layout of my mother board
http://www.ecs.com.tw/ECSWebSite/images/Products/large/H81H3-I_V1_HDMI_LGA_1150_Intel_Motherboard_2.1.jpg
http://www.ecs.com.tw/ECSWebSite/images/Products/large/H81H3-I_V1_HDMI_LGA_1150_Intel_Motherboard_3.1.jpg
the two four pin headers above and below of sata port is cpu fan header and system fan header
the one close to cpu is the system fan header
by the way my cpu fan with heat sync have 4 wires which is connected in a system fan port
here is the whole layout of my mother board
http://www.ecs.com.tw/ECSWebSite/images/Products/large/H81H3-I_V1_HDMI_LGA_1150_Intel_Motherboard_2.1.jpg
http://www.ecs.com.tw/ECSWebSite/images/Products/large/H81H3-I_V1_HDMI_LGA_1150_Intel_Motherboard_3.1.jpg
the two four pin headers above and below of sata port is cpu fan header and system fan header
the one close to cpu is the system fan header