2 Replies Latest reply on Feb 10, 2014 5:29 AM by Nomos

    DZ87KLT-75K / PWM / Fan-Control

    Nomos

      Moin Moin


      First of all sorrs for my English.


      Mainboard: DZ87KLT-75K

      BIOS: 0446

      CPU-FAN: Zalman_CNPS9900_MAX_RED

      Case-FAN: Coolink_SWiF2-120P (Front and Rear)

       

      Question:

      How can i control the Fans (PWM) with the BIOS

       

      I now that i can change the minimum Duty Cycle.

      I have tried to change it to get the fans to min. U/min.

       

      On the Intel Mainboard DP67BG-B3 this works.

      But on the DZ87KLT-75K nothing works.

      I can set the min. Duty Cycle to 1% and the fan is still running 1000 U/min. instead of 800 U/min.

       

      Thanks for HELP

       

      Mfg Nomos

        • 1. Re: DZ87KLT-75K / PWM / Fan-Control
          spearson

          Nomos,

           

          You haven't been very clear regarding what you are actually trying to accomplish - what you think is wrong and needs fixing. Please restate in terms of your goal(s) for wanting to make any changes.

           

          If you simply want to manually control a fan (i.e. set them to a fixed duty cycle), you can change the Control Mode to Manual and then use the Minimum Duty Cycle parameter to select the duty cycle that the fan will run at.

           

          In the case of the Processor Fan (and any other fan header that has a 4-wire PWM-controlled fan attached), you need to take into account what type of duty cycle response is implemented within the fan. Every fan has a minimum duty cycle that it can reliably maintain. The 4-wire fan specification (available here: http://www.formfactors.org/developer/specs/4_Wire_PWM_Spec.pdf) details three ways that the fan is allowed to respond to duty cycle settings that are below this minimum:

           

          1. (Type A) As the duty cycle drops below the supported minimum, the fan will continue to operate as if the duty cycle was set to its supported minimum (i.e. it does not slow down any further).
          2. (Type B) As the duty cycle drops below the supported minimum, the fan will continue to operate as if the duty cycle was set to its supported minimum. When the duty cycle reaches 0 (zero), however, the fan will stop spinning altogether..
          3. (Type C) As the duty cycle drops below the supported minimum, the fan will attempt to slow down accordingly. At some specific duty cycle, the fan will be unable to maintain spin and will stop.

           

          The Zalman site's information is anemic; they don't say anything about minimum duty cycle or operational mode. The unit's thermal dissipation is top notch, however, so if your concern is that you never see the fan speeding up, it's likely because... it doesn't need to! You mentioned not being able to get the speed to go down to 800RPM. The reason for this is that this fan's minimum speed is listed as 900RPM. Unless it is a Type C fan - which is pretty rare - you are not going to be able to get it to run at 800RPM; it just won't go that low!

           

          I also checked the Coolink site; same story; they don't publish this information either. Spec-wise, though, these look like really good quality fans. I recommend that everyone use 4-wire PWM-controlled fans, so good choice there...

           

          ...Scott

          • 2. Re: DZ87KLT-75K / PWM / Fan-Control
            Nomos

            Thanks spearson

             

            "If you simply want to manually control a fan (i.e. set them to a fixed duty cycle), you can change the Control Mode to Manual and then use the Minimum Duty Cycle parameter to select the duty cycle that the fan will run at."

             

            You mean here:

            IMG_1086.JPG

            Because when I change here:

            IMG_1087.JPG

            to manual nothing happens.

             

            I tried to explain here:

            I can set the min. Duty Cycle to 1% and the fan is still running 1000 U/min. instead of 800 U/min.

            I did mean the: Coolink_SWiF2-120P.

             

            But I thout about this:

            "Spec-wise, though, these look like really good quality fans."

            I changes evers FAN (Front, Rear, CPU) to: NB-eLoop B12-PS PWM.

            Now I am Happy. Because every FAN has the min. U/min.

             

            Mfg Nomos