On Wed, Feb 23, 2011 at 12:00:57AM -0500, Phillip Susi wrote: > On 02/22/2011 09:46 PM, Guenter Roeck wrote: > > > How many fan counters (fanX_input) do you see on your system ? > > The device reports 5 fan inputs and 3 pwm outputs, but the motherboard > only has 4 fan headers: 2 4 pin and 2 3 pin. From that I would expect > pwm1 and pwm2 to be routed to the two 4 pin fan headers ( first one is > cpu ), and the other two fan headers input to be connected to fan inputs > 3 and 4, with no control. > pwm2 is the CPU fan, actually. How does the "sensors" output look like before and after you change pwm1 ? > > I am a bit confused about the correlation of pwm to inputs and fan behavior. > > Are you saying that pwm1 affects three of the four fans ? That would be a bit odd. > > What are the values repoted by pwm2 and pwm3, and do you see anything change > > if you modify those values ? > > Indeed, it is odd. If I set pwm1 to a value of zero, all but one of the > fans in the system stop. Specifically the cpu fan, the front case fan, > and the rear case fan stop, while the top case fan continues to spin. I > will need to open it back up to make sure, but my guess is that the top > fan is connected to the second 4 pin fan header on the motherboard, but > since the fan is only a 3 pin fan, it does not respond to the pwm output > that is likely connected to it from pwm2. The other two fan headers are > only 3 pin headers, but since they seem to respond to changes to pwm1, I > guess that the motherboard has on board FETs that respond to PWM1 to > regulate the voltage on these two headers so their speed corresponds to > the cpu fan speed. > Actually, sysfanout (pwm1) can be configured for DC output. You should see the setting with pwm1_mode. If its value is 0, output is DC, otherwise it is pwm. pwm2 and pwm3 only support pwm mode. If configured for DC, the upper 6 bit of pwmX translate to output voltage. Motherboard pinout (per its datasheet) is a bit odd. Looks like only the CPU fan (pwm2) supports pwm mode. The other fan connectors don't have a pwm pin. Fan connectors are labeled PWR_FAN1, CPU_FAN, CHA_FAN1 and CHA_FAN2. CHA_FAN1 has a 4-pin header, but the 4th pin is labeled as "+5V", not pwm. > > Would it be possible to run pwmconfig and let us know what it reports ? > > It appears to agree with my assessment in that fan1 responds to pwm1. And pwm2 and pwm3 don't have an effect ? Also - just trying to make sure - if you change pwm1, does it have an effect on pwm2 and/or pwm3 ? It should not, but who knows. And what are the values reported by pwm2 and pwm3 ? Thanks, Guenter _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
