Settings - Fan
The Fan section really exists of 3 parts; at the top you have the sensor selection and at the bottom you have the alarm and visual section for the selected sensor. So if you select a new sensor then the Alarm and Visual section will change according to the settings for the selected sensor. This means that you can/must configure each sensor on it's own.
MBM Fan sensor
MBM 5 can show you up to 16 fans, the one you select here determines to what sensor all the others changes you make on this tab are applied
Should display board sensor
This list shows the avaible fans on your motherboard, you hook them to 1 of the 16 MBM 5 fans. Only select Custom if you plan on using that fan with an external program who will write to that slot, see the Write Shared Memory section for more detail on that.
Fan Type
Some Fans will show a too high RPM or a to low RPM as the pulses they send per second don't match what the sensor chip expects.
There are 11 settings, /1 to /10 which divide the readings by that amount and *2 which muliplies the reading by 2. Default setting for 99% of all boards will be /1
Fan Dividor
Default this value is 4, this means that fans as low as 1300 rpm will show up, the lower you set this value the more accurate the fan RPM will be, but if you set it to low your fan might not show up. Not all sensor chip support values higher then 8, if yours does not then selecting 16, 32, 64, or 128 will simply make mbm use the 8
Check the little table below:
Dividor Minimal RPM Highest RPM Use in most cases for: 1 5300 1350000 2 2650 675000 CPU Fans 4 1325 337500 Case Fans 8 662 168750 16 331 84375 32 165 42187 64 82 21093 128 41 10546