KN9 Cpu fan control?

[musicman53]

Hi,
goin from an AN8 to a KN9 and will use a heatsink fan with the regular 3 pin connector on.
I tend to either set the speed in the bios or use uGuru program to set the cpu and other fan speed(Quiet, Cool or whatever I choose).
I don't use Cool and Quiet at all.
I see that the info for the KN9 shows that if you use a 3 pin connector then there is no control over the fan speed.
That sounds strange to me as the 3 pins on the board do the same as on the AN8(12v, ground and rpm).
Why does it need a four pin fan before you can have any control over the cpu fan speed?
The number 4 pin is marked control?
Control by what means?
Cool and Quiet?
Or FanEQ?
And what about all the other fans anyone might want in the case?
No control at all over their speed?

[BUFF]

the CPU Fan control on abit AM2 mobos uses PWM like on current Intel HSFs but there aren't too many AM2 HSFs with PWM fans afaik (I believe that Artic Cooling 's does though).
You should still be able to have fan control on a 3-pin fan by connecting it to the Sysfan1 header instead & in the BIOS setting the SysfanEq ref. temp to CPU instead of System.
Remember that the KN9 doesn't have uGuru so I'm not sure that you will have the Cool, Quiet etc. options.