I have had the 975xbx2 for a few years, been a great board. I recently upgraded to a 2600k and the DP67BG board. I am probably what you would call an advanced user.
On my xbx2, the BIOS did not give options really for fan control, but the desktop utility software did (one of those softwares, there were 2, the IDCC and IDU or something like that). Anyway, I was able to stop using SpeedFan when I found the desktop utility could save my fan profiles to the BIOS.
I researched a lot of boards for this purchase, and decided to go with Intel for many reasons, one of which was the fan control in the BIOS. However, it is not doing what I had anticipated from reading the manual/bios pdf files nor from what reviews and screenshots I have seen.
On my xbx2, the CPU, the Front/Rear and the AUX were 3 unique, controllable items. On this DP67BG, it seems much the same, where the CPU, the Front and the Rear/Aux are each a unique item. Speedfan seems to concur this, and does give me control over them, individually.
However, I was hoping to be able to control the fans a little better. So here are the questions.
It appears that the CPU is the only fan that will positively be controlled in an expected fashion. If you disregard the PWM %, and assume that all fan headers will run between 20 and 100%, I find that only the CPU header actually regulates its speed according to the parameters you can use in the BIOS. Those parameters are the temp you wish to maintain, and the temp at which the BIOS should take control of all fans. I read this to say that, for any of the 4 temp readings (CPU, MCH, RAM and VR), the BIOS will attempt to maintain a target temp, and if it goes above the upper limit, then all fans will be employed.
I do not see this happening though. I see the CPU does this, it follows an alogrithm. But what is the algorithm. How much do the different aggresiveness and dampning options come into play? What is the thresholds for the value? If you set CPU to maintain 50 deg, at what point do fans speed up? At 10 deg < setpoint, they begin? At the setpoint, the go to 100%
Further, the high limit, even for CPU, never seems to employ the other fans. I have all good quality PWM fans on my board. The only way I can get the BIOS to raise the speed on the other fans is to go into one of the other temps (MCH, RAM or VR), and set the temp to maintain very close to or below the temps at which those components are going to run at. But they still don't speed up or down on thier own, they just maintain a faster rpm rate.
I have rebooted dozens of times, modifying many of the aspects of the BIOS fan control. Only the CPU fan seems to do what I would expect. The verbage in the BIOS leads me to believe the other fans will also do the same. If I run the stability test, and purposefully set my BIOS values so that the temps and thier settings should force the high limit to be achieved, the fans other than CPU do nothing.
In fact, the MCH, RAM nor VR temp limits, neither maintain or high limit, have any effect at all !
Does anyone know, does the MCH control one fan header specifically unless its high temp limit is reached? The same with the RAM and VR, do they control specific fan headers? Or are they all married together.
Also, is the DP67BG (version B3) supposed to have fan control of each fan header inidividually, or are 2 of them married like they were in the xbx2? What about the different options for each fan header, in reference to what type of fan it is. You can choose CPU, System, Chassis, Inlet, Outlet, MCH, VREG, etc etc etc. But what is this supposed to do? Is it only for my own organization? Or by setting all fans to CPU should they all be controlled by the CPU. Or, is there an alogrithm that changes based on which setting you use?
I realize this is the community support forum. I don't fully expect an official Intel employee to see this and provide answers. I hope that happens. I hope that anyone who knows about this more technical stuff can share some insight with me. Or, at the very least. inform me of how I might get in touch with the right person at Intel who could answer these questions.
I am no fanboy of either camp. I like Intel because they are worth the money for the performance right now, the same as AMD was when they first came out with the Athlon64. I am not devoted to Intel motherboards, as I have used many different brands over the years. But I am devoted to stability, quality and features. Intel makes a lot of great products that IMO are superior to most others, the network adapters being a great example. My last dozen machines I have used or built were based on Intel processors and boards, and I have been very happy. I chose the DP67BG due to this experience and what it offers. If the fan control is limited to the CPU only in the BIOS, then I feel a bit misled. I could have purchased other motherboards that offered more SATA 6 ports, internal USB3 headers, etc etc if I had known one of my major criteria was skewed.
Any help is greatly appreciated.