Well , I had email Gigabyte asking about the CPU temperature scaling VS the rpm speed scaling of the PWM control circuitry .
The specific motherboard offers zero manual control of the fan speeds.
The reply that I got was that if the CPU become hot as 40C , the fan operates at full speed .
If its below 40C , it works at the lower fixed speed.
About the VGA and motherboard temp , it looks that Gigabyte and possibly others , they count on the VGA cooler , that it will cool down and the nearby PCB of the motherboard too.
I received just yesterday, my new Sapphire 5770 , and the on board cooler, it does cause an strong air circulation = all around ventilation = it cools down the
south-bridge + and the drops down the PCB sensor temperature.
The first picture shows how well it cools down the
south-bridge.
The
second , its an example of the bottom air circulation path,
all those blueish tint represents the "air circulation".
All that I can imagine are, that slot type GPU coolers does not do that.
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