I have a PWM fan plugged into the AUX fan header of my Z68BC, which feeds air to a separate PSU compartment in my case (Antec P183).
BIOS allows me so set values for automatic control of this fan (i.e. min/max duty cycle).
However...the actual AUX fan RPM's are kept in lockstep with the Rear Exhaust fan settings, no matter what values I load in BIOS. I can enter 100%min duty cycle on Auto control and this fan still runs as per the "Rear Exhaust" settings.
Also, if I update the BIOS label for this fan from "Aux" to "PSU In", I misteriously lose the ability to read its RPM's in BIOS or using the Intel monitoring app.
Is this behavior by design, or do I need to worry about updating my BIOS?
I'm in disbelief that Intel would provide a separate fan header and independent BIOS setting prompts only to ignore the settings.
MB DZ68BC version AAG30742-401
There was a discussion on this forum about the fans on the DZ68BC:
The main answer was:
There was also somewere else on this forum the remark that if you rename the labels, the settings of the intel monitoring app need to be reset otherwise the readings will not correct anymore.
It seems that your are using version 0021 of the BIOS. There is already version 0027. The BIOS release notes provide an overview what Intel has fixed:
http://downloadmirror.intel.com/20538/eng/BC_0027_ReleaseNotes.pdf (actually a substantial list)
On my DZ68BC version 0027 runs fine.
I have discussed the label issue separately; this is a BIOS bug (changing the Usage label should NOT affect fan control or monitoring ability) and it is getting fixed.
Regarding your other question, you have to understand that the SIO being utilized provides only 3 fan speed controllers and we are providing connection points for 4 fans. Obviously, two of these fans have to share a fan speed controller output. In this case, it is the Rear (Outlet) and Aux fans that share a controller. Thus, the answer is it's-by-design. As for the settings, you should notice that, if you change the settings in the Aux fan's configuration page, the settings will also change in the Rear fan's configuration page (though, in some cases, it may take a reboot to see this)...
Thank You for the responses.
Understood about the Exhaust and Aux headers sharing PWM control. However, the behaviour you describe, about being able to change BIOS settings on either Exhaust or Aux and the setting impacting both is not what I experienced with BIOS BCZ6810H.86A.0021.
I reset the settings of the Aux and rebooted several times, upping the AUX Min Duty Cycle from 20, to 35, to 45, to 65, to 100, and this caused no change in the speed of either fan (Rear Exhaust or Aux).
Only when I went to the Rear Exhaust fan control and upped that one to 100%, did I realize both headers were being lockstepped.
So my experience is the AUX Duty Cycle settings are just ignored (at least in Auto mode...didn't try manual control).
A prior poster recommended I update my BIOS from BCZ6810H.86A.0021 to the more recent BCZ6810H.86A.0027.
After doing that, my PC goes through POST, and only begins loading Win7-64 before throwing a BSD, and cycles back to BIOS restart...endless loop.
Win Boot Repair or Restore are no help.
The BSD flashes for such a split second, I'm unable to even read what it says. I may record it with a sports camera, see if I can slow-motion and read its content.
I'll also try creating a BIOS CD-ROM to attempt to take the MB back to BIOS BCZ6810H.86A.0021.
Oh well...building your own PC is certainly not for the faint of heart!
I tried reverting my BIOS back to 0021, by attempting to update directly from the BIOS [F7] update with no success. It kept reporting the "Engine....is blacklisted. Fail!"
After several attempts I recorded the BOSD on a high-speed camcorder to read the text of BOSD. It was up for only 3 frames at 60fps. Windows telling me to check for virus or to remove any new hardware, as disk drive.
BSOD seems to have been caused by the BIOS update process.
Updating to version BCZ6810H.86A.0027 using the .exe windows BIOS update app, seems it reverted the SATA settings to default, which created BOSD at boot.
After setting back to RAID (I use SRT functionality), Win7 was able to boot...BUT:
The BIOS update utility reports the BIOS update was "unsuccessful".
The BIOS version is reported correctly: no longer 0021, and now 0027, and the PC is booting OK now.
Any suggestions are appreciated if corrective action is needed.
On my original issue of the fans, I'll reconfigure the headers such that case intake fan is plugged to the Aux fan header. This way when Exhaust revs up in response to higher board temps I have better airflow in & out. Once the new corrected BIOS is out, I hope to update all the labels appropriately.
Sorry to hear that you had so much trouble with the BIOS update. The .exe update mechanism also failed on my system, but as I am running Window 8 preview I just ignored that and switched to the F7 method. I was even positive surprised that with F7 it is possible to load the bios image from a NTFS internal harddisk, I always misplace my USB memory sticks :-).
The AHCI\RAID mode has also biten me twice:
- After my initial system build and configuration I wanted to add some hard disks and then discovered that I needed to reinstall the OS my primary SDD boot disk when you change this setting (at least it is documented..).
- When you reset the BIOS settings to default then this setting is also reset to AHCI as this is the BIOS default value, causing the system to fail booting. Very confusing if your are busy in an overclock session.