- one with Fanspeed info tab, that says "no known chipset detected".
I guess you can forget that information, usually it doesn't matter at all: in my experience I never look at that tab, as SpeedFan actually deal with the Super I/O chip (the interface of the chipset).
The MSI B85M-G43 (MS-7823) is not in the list of Fanspeed supported Mobo.
It doesn't matter at all too, as that list is buit by user feedbacks.
I confirm that in the BIOS, the min setting for the CPU fan is 12,5%, but the difference with 20% in detected RPMs is not obvious. I feel that it is not really an issue as the Scythe fan is very quiet. In the BIOS, the min setting for the SysFan1 is still 50% => too high. I would be really happy to lower this speed.
The real difference between SpeedFan and most of monitoring tools is that SpeedFan need to be fully configured before using it satisfactorily: I'm used to say it has a rather steep learning curve, our appreciated co-forumer Abula hate that, often summarizing that SpeedFan is unable to correctly identify the sensors out of the box.
Anyway, you need to configure SpeedFan: usually I do that with the help of another monitoring interface, my choice is HWiNFO, but you may use Open Hardware Monitor, or the paid clone Hardware Monitor (indeed OHM is the actual open source clone).
Well, running the HWiNFO Sensors window along with SpeedFan I look for matching the sensors on both the programs: in your case, it look like the 128°C temp is a stuck sensor, which probably HWiNFO won't detect at all, and I use the temp values as a guide (when the values are the same, probably it's the same sensor, despite of the name; varying the fan speed, whether the relevant temps change the same way, I'm sure it's the same sensor).
Just for the cores temperature, as it's an arbitrary scale, I use a different calibration tool: my choice is Real Temp 3.70, but you can use CoreTemp also, but even HWiNFo isn't so far from Real Temp readings, usually.
Well, when I've indetified all the mysterious sensors, I disable all the unnecessary ones into the Configuration tab (unchecking the relevant control boxes) and I rename the useful ones (click on the name until it highlights) in a meaningful way.
Then I will bind those useful sensors to the relevant fan speeds I want to control: so click on the "plus" sign and check any relevant box, and finally set the relevant Temp thresholds (desired and warning).
The second step is to disable all the unused reported fan header under the Fan tab, renaming the useful ones in a meaningful way (such as "CPU Fan", or "Case Fan", and so on).
After that, I will set the base parameters for each active fan under the Speed tab: I disable any speed I won't use, I check the "automatically varied" box for any fan I want to control, and set the the relevant Speed thresholds (min and max): take note that after the Warning Temp threshold, any automatically varied fan will spin at 100%.
Eventually you should set the Super I/O chip behaviour, as shown there
, and you will also set the needed offset for cores temps.
This is very briefly what you need to do, at least: providing you correctly perform all that, whether it still won't work, then you may reasonably conclude that your motherboard (actually its Super I/O chip) is not compatible.
So, have a good luck (in case)!