PWM FAN Speed Control & Slope. Z77-D3H.

[P . P . L .]

Hi.

Anyone know what this means in english, what does the value over oC stand for rpm's or % or something else.?

Manual. Options are: 0.75 PWM value /oC ~ 2.50 PWM value /oC. & CPU Fan Speed Control & Slope PWM

I'm trying to get my cpu fan to slow down more, their suppose to go down to 500rpm when cpu is cool but it doesn't it stays at around 1000rpm idle then it will go up to about 1500rpm under load room temp is 20c or less.

Running 2 fans pwm, I've tried auto & pwm in the bios it doesn't make a difference I was going to try manual and set the slope but which one.?

[P . P . L .]

What no one knows, well something fishy going on with this because I've tried 3 different PWM fans 2 had starting rpm's
of 500 the other is 600rpm.

The bios won't make the fan run below 1000rpm even at a room temp of 12c( winters coming down here ) with the cpu idling at 1.6ghz and temp showing as 18c.

I've tried setting the slope manually to 1/0c still makes no difference, fan is still running at over 1000rpm at idle so is the bios broken or what anyone know if any of the new bios have a fix for this?

Edit/ These are the 3 fans I've tried.

Deep cool that came with the cooler / 500 - 1500rpm +/- 10%.
Nexus real silent / 500 - 2000rpm +/- 10%.
Cooler Master XTRAFLO / 800 - 2200rpm +/- 10%.

[P . P . L .]

So no one else is having a problem with their cpu fan speed, must be just me then.

O.K. if you have the same board & revision as me, please let me know what bios & type of cooler/fans your using plus what speeds the fan runs at from idle to load.

thanks.

[P . P . L .]

Well I give up, I went to the extreme of updating the BIOS to F18 to see if that would fix this fan problem

and guess what it didn't change a thing. It's still running to fast for the low temps I'm getting see below.

Room Temp is 22c.

edit/ CPU speed is at 3.9Ghz all cores/threads pushed by Ubuntu of course. 

CPU at full load 8 threads folding Temp is 49c - 54c across the four cores.

M/B Temp is 24c.

CPU fans are at 1708rpm.

[P . P . L .]

Well some good news, it looks like a being shut down over night & a cold boot has reset the the pwm chip or whatever regulates the fans

speeds because this morning the cpu fan was down to 870rpm from the start & has only gone up slowly with the temps.

I suppose the bios update was the main thing, it just needed to be powdered down so hopefully it keeps working like this.

[Grus]

On BIOS 22 is a problem with the fan speed control. When you boot up from off state you have a CPU-temperature depend speed on ALL fans ( pwm or voltage control). But when you reset system and boot not from off state you have a  CPU-temperature depend on CPU FAN and system-temperature depend on other fans.

On BIOS 23b you always have CPU-temperature depend on CPU FAN and system-temperature depend on other fans.

That is crazy. To understood that behavior i spend 2 days and abt 40 reboots. Facepalm.