The dumbest thing ever, CPU fan thermal sensors

[Arkade]

We aren't talking about attaching them by cables, but apparently alot of AMD stock fans have thermal sensors attached right on the PCB.

So I went ahead and took a hot air station to one of these fans and the RPM shot skyhigh. One of them even had PWM but the PWM wouldn't even bring it to top speed. So then i tried something. I stoped the fan with my finger so it would overheat the heatsink. I got the CPU to 80C and released the fan. It was still at the lowest possible speed because the thermal sensor. I removed it and soldered past it. Fan moves much more air now. What was the purpose of these stupid thermal sensors when most boards have automatic fan control of some kind?

I'm making a video to show what I'm speaking of.

 

[Mr.Scott]

A little blob of solder bridging the two sensor legs will take care of everything.

 

[Arkade]

Exactly how I'm adjusting all the fans right now.

 

[Arkade]

 

[m0r7if3r]

Was that the fan that came with the heatsink?

 

[Arkade]

Yes, but it's with alot of fans I have. the fan in the video is an AVC fan, and the one in the first post is a Delta

 

[NiHaoMike]

It's intended for use as an exhaust fan.

 

[Arkade]

But they are mounted factory on heatsinks as intakes.

 

[NiHaoMike]

You can't expect the engineers at AMD to know everything. Or maybe it was intended to compensate for differences in ambient temperature.

"Smart" fans are among the most kludged ideas in PC engineering. More often than not, the setpoints are way too high and some (like the example you posted) even do it completely wrong. But when it's done right, it works very well.

 

[m0r7if3r]

You can't expect the engineers at AMD to know everything. Or maybe it was intended to compensate for differences in ambient temperature.

I wouldn't expect the engineers at AMD to be familiar with whale anatomy, but picking an appropriate fan for a heatsink should be WELL within their wheelhouse. If everything is as this thread makes it out to be, then it was either designed to operate that way, or marketing got their hands on it once the engineering department was done with it. Most people don't want maximum cooling. Most people want sufficient cooling with minimal noise.

 

[Arkade]

The thing that made no sense is motherboards have PWM or some method of fan control. I tested the Fans in stock setups and they never ever sped up. They remained at the lowest speed all the time. It just is mine blowing.