how do you connect case fans?

[new2toms]

I have ordered GIGABYTE GA-EP35-DS3P P35 and two Scythe S-FLEX SFF21F 120mm Case Fan http://www.newegg.com/Product/Product.aspx?Item=N82E16835185006 among other things for my new system. This fan comes with a 4pin adopter with a male/female molex connector. Here is what confuses me; While reading the motherboard manual I found that it has only one 3 pin sys_fan header and a one 4-pin sys_fan header. So on one fan I can connect it's 3-pin to supplied 4-pin adopter and plug it into the motherboard fan header and connect the molex connector to the power supply but what do I do with the second fan? If I just plug it into the 3-pin header then don't I need to connect it to the power supply? and if I do then there is no molex connector for that. As you may have read from my previous posts that I am a newbie and this is confusing to me. Thanks for any help.

Gigabyte Manual:

The motherboard has a 4-pin CPU fan header (CPU_FAN), a 3-pin (SYS_FAN1) and a 4-pin
(SYS_FAN2) system fan headers, and a 3-pin power fan header (PWR_FAN)...

 

[sciggy]

Generally if you can connect to the fan header on your mobo. That will allow you to monitor RPMs and such in windows (good to know if the fan is working) If you go this route, you do not need to plug it in to the molex connector. The adapter plugs into the 3 or 4 pin on the fan and converts to the molex. Either way will power the fan, its just a matter of being able to monitor the fan in windows and adjust the speed.

 

[leo2kp]

Many 4-pin fan plugins will work with the 3-pin headers.

 

[rwpritchett]

The 4-pin fan header you read about in the motherboard manual is not the molex 4-pin type like the adapters. They are PWM controlled headers. A 3-pin fan plugs in fine to a 4-pin PWM header BTW.