Some Antec (and other) power supplies have connectors for fans to keep them quiet when the PSU is not hot.
If im not mistaken those "fan" leads are there to provide independent power for fans (kinda like minirails) or if you're talking about the other conectors, to provide RPM data
Also some new motherboards have 3 pins for 3 fans
And some have four... five etc
Do the motherboards control the fan speed when the processor gets hot - or should you stick with the PSU connectors to regulate the fan speed?
1. AGain im not so sure about what you mean by those PSU connectors (which antec are you talking about)
2 Most modern mobos do support fan speed controls
Do you mean, stick with the PSU? I couldn't be bothered getting a fan regulator that is manually controlled.
Then get an automatic one
Can you imagine constantly turning the thing up and down.
1. Why would you constantly?
2. Leave it at max
Does the mobo control the speed of case fans?
It can
As far as I know, new mobos have a 4-pin controller for the CPU heatsink which controlls the speed based on temp
They do? (are you sure you're not mixing this up with the P4 12V ATX?)
which I believe means that they are ineffecient at controlling speed
That extra pin is for rpm telemetry not control. Contorl is done via the other two pins
