Fan Speed Problems

[t0rek]

I've been using Speedfan for a couple of days, and it's great. However, after these I have a problem. The RPMs of my CPU and case fans are starting to show wrong (0 RPM) randomly, even when the fans are working well. I already tried other monitoring programs, and even the BIOS monitoring has this problem. This occurs randomly as I say, and most of the time with the case fan. What could happened?

 

[smcd]

Have you checked that all wires are securely connected? Tried uninstalling Speedfan (likely wouldn't help with the BIOS part but just a thought)?

 

[t0rek]

All the wires are properly connected, and I already tried unistalling speedfan without results... Here is a screenshot of what I mean, taked with the fans clearly spinning...

 

[cooliscool]

Software can't read fan speed unless the fan(s) have yellow (detection) wires.

 

[t0rek]

Software can't read fan speed unless the fan(s) have yellow (detection) wires.

I'm aware of that.

UPDATE: it seems to be a some speedfan / hardware issue. When I open MSI's bundled Core Center program, it starts to read the fans RPMs again. However, if the problem shows up again, it doesn't dissapears (even in the BIOS), only if I run the crappy Core Center, it gets fixed again. Really weird isn't ?

 

[zAlbee]

Read the <a href=http://www.almico.com/sffaq.php>F.A.Q</a>?

<i>My fans are showing odd RPMs or 0 when slowed down</i>
Fan speed control is achieved by accessing some features available in some hardware monitor chip or some other special hardware. These chips might be able to controls fan speeds. They usually do this by using PWM output. A PWM digital ouput is a digital signal that alternates some levels very fast, thus simulating some intermediate average level. The net result is a perceived average voltage lower than the usual one. Please note that some chips (very few of them) are able to lower the voltage without PWM simulation.
The fans, on the other hand, can report their speeds (RPM) by using some internal sensors that report how often some current flows between two plates. Fans are built assuming nominal voltages and a continuous signal. When voltages are lowered or modulated through PWM, some fans are no longer able to properly trigger when those plates face each other and resulting fan speeds may show odd values. SpeedFan works flawlessly even in such situations.

 

[t0rek]

Yeah I did it, but that's too technical for me, if someone knows to "translate that" and solve my my problem I will be very pleased.

 

[zAlbee]

Basically, to lower the speed of the fans, the motherboard has to lower the voltage. Some boards do this by changing the voltage very quickly between 0 V and max V, so that the average voltage is lower (this is called PWM). This messes up the ability of the fan to count the RPM.

I suggest you try to not lower the fan speeds and see if it stays.

 

[t0rek]

I think that PWM issue must be Speedfan related, because when I open Corecenter, the problem get fixed both on Speedfan and Corecenter, so I close Corecenter, and let speedfan working. I have to do this every time I turn on my PC

 

[DOGG]

sometimes, if the fan speed is too low or high, it will give invalid readings.

an example is my cpu fan. when it slows down (mobo temp controlled), the readings show speeds of +20,000 to -20,000 RPM and such. If it speeds up again, the readings go back to normal.