Which GTX970 model to choose?

Question

Iron

GIGABYTE GV-N970IX-4GD or GIGABYTE GV-N970WF3-4GD ?
Which video card is quieter? (head-to-head comparison of 1 and 3 coolers is incorrect, because for the same cooling, 3 coolers will rotate at a lower speed than one)
Why, with the same characteristics, do they differ in the "estimates" of sites?
Should I take a video card from the GIGABYTE OS (Overclocking) series?
Or is it generally better to choose some other video card?
PS: Please DO NOT offer 980, 1070, 1080 or NOT GIGABYTE.

Answer 1

they differ because boost has not been canceled, the better the cooling, the more auto-acceleration will set the frequency.

Answer 2

And I think they are the same