On Fri, Jun 25, 2010 at 11:17:08AM +0200, Jean Delvare wrote: > > Can you please wait a bit in this screen and try to gather other sample > values for +12V? If you can gather 2 or 3 different samples, we may be > able to guess the scaling factor. > > 2.62V in sensors for 11.776V in the BIOS suggests a scaling factor of > about 4.5. For something more accurate, we need more samples from both > the BIOS (see above) and the it87 driver. "sensors" only displays 2 > decimal places, so better get the exact reading from sysfs directly: > > cat /sys/class/hwmon/hwmon*/device/in4_input > > If you can gather 2 or 3 samples of each, finding the scaling factor > should be reasonably easy. Good idea. I temporarily modified /usr/sbin/fancontrol to log the in4 to a file, so the values would be logged right before and after reboot, i.e. close in time to my BIOS readout. The BIOS +12V readout changes in increments of 64mV and the in4 in increments of 16mV. The ratio between the values is exactly 4. > > (I wonder if this could have the slightest relevance, but my board is > > powered by a 200W PW-200-M from MINI-Box). > > Wow, this is cute :) Yes, this probably explains why your voltages are > rather below the average. Thanks. :-) Since my BIOS +12V was quite a bit below 12V, I took the opportunity to increase the voltage of my external 12V PSU, since this caused the +12V to increase. The new +12V and in4 voltages also have a ratio of exactly 4. Unfortunately, the in4 readout seems to indicate that the voltage on the +12V rail of my PW-200-M drops when the CPU goes from idle to fully loaded. With a short, thick (load-speaker) cable between the PW-200-M and the external 12V PSU this drop is 128mV, with a longer, thinner cable this drop can exceed 600mV. :-( But now I can at least monitor my +12V via LM sensors. :-) > We can write the sensor chip drivers (and have done so for many > already: LM63, LM99 etc.) but the I2C access to these chips is the > graphics driver's job. Which are improving over time in this respect, > so it should work someday. I'm not actively working on this though > (probably due to the lack of nVidia card in my systems.) OK, thanks for the info. I have updated http://www.eso.org/~llundin/sff/sensors.conf with the complete voltage labeling + scaling. Many thanks for helping with this, -Lars Lundin. PS. I have one or two other mainboards. If I happen to find some new configuration info for them, what is the best way to provide that to the LM sensors project? _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
