Hi Leo, On Sun, 29 Aug 2010 01:16:17 +0200, Leo Krüger wrote: > I own a MSI IM-945GSE-A motherboard and used the sample configuration file > from http://lm-sensors.org/wiki/Configurations/MSI/IM-945GSE-A, > which showed me around 14V for the 12V output. I'm adding the original author of the configuration file to Cc. > Since this would be far above specification limits, I measured the actual > values at the ATX power connector. In addition to the 12V output, the 5V > and the 5Vsb line differed a little. I am a little curious about your experimental setup. How do you get access to the ATX power connector while the system is running? I usually measure +5V and +12V from molex connectors, it's easy. But 5VSB, I wouldn't know how to measure it. > Below is my updated configuration file. Note that I just changed 3 lines, > the compute lines for in4, in5 and in6. > It would be nice if you could update the sample file in your wiki. > Let me know if any additional steps are necessary. It is expected that measuring the values with a multimeter will lead to slightly different results for voltages which need scaling. Scaling is achieved using two resistors, the value of which is typically guaranteed to 1%. Therefore, there can be up to 2% of error introduced by the resistors themselves. By calibrating your configuration file based on actual measurement, you correct this error for your specific motherboard, but the same correction doesn't apply to other instances of this motherboard model. So your proposed changes may be perfect for your board, but aren't suitable for the default configuration file for this board. A better way to figure out which scaling factors are intended by the board manufacturer, is to compare with what the BIOS is printing. First write down all values reported by the BIOS, and also note your voltmeter measurement. Then do the same again with lm-sensors's unscaled voltage values. If the voltmeter values didn't change, then lm-sensors should report the same as the BIOS after scaling. If the voltmeter values changed (which can happen as the system load is slightly different) then you have to take it into account in your computations. The 5.25 scaling factor comes straight from the datasheet (suggested resistors of 200k and 47k), and your own measurement for +5V leads to almost exactly this, so I wouldn't change it. It is also quite unlikely that the vendor would use different resistor values for +5V and 5VSB, which makes me reluctant to change 5VSB either, although your proposal is quite different there. For +12V, the 12.83 scaling factor was apparently copied from our old default configuration file, which for this chip was written for an Epox board. The datasheet instead suggests to use resistors of 200k and 20k, leading to a scaling factor of 11. Note that the difference between this 11 and your 10.86 is less than 2%, so it is likely that MSI followed to the datasheet. So I would go with 11. -- Jean Delvare http://khali.linux-fr.org/wishlist.html _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
