As you can tell from 7020 mt motherboard chassis fan header (SYS FAN header) uses Dell proprietary 5 pin (4 wire) latch style connector which means you cannot use the 80 mm 4 pin Noctua fan without an adapter like this one.

thank you so much!  I have a follow-up question .. id like to use a 120mm fan at the front, would a SATA 15 pin be ok? 

It will be ok if you use a sata male to 2 pin fan adapter.  The adapter only wires the 12V and gnd of the 15 pin sata (leaving the 3.3V and 5V of sata unwired).  You can connect the 120 mm Corsair fan to the 2 pin socket of adapter.  The fan would be spinning at constant rpm off 12V.  No tach read back of fan rpm and no PWM because only 2 out of 4 pins of the fan are wired.

The psu sata 15 pin can support hdd 3.5” which goes up to 7 to 9w.  typical fan has power < 2w.  so each sata 15 pin can power up to 4 such fans.  therefore you see some adapters of sata to 4 x fan connectors.

fan will be running 100% so it better be a quiet one.  other than that you get high air flow.

much appreciated, you have been very helpful ! , youtube and google couldn't give me a great lead and understanding of the cables. thank you once again. 

would fan speed be an issue? thank you for your help 

120mm fan won't fit in the front.  Use 90-92mm fan.