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| author | Jean Delvare <khali@linux-fr.org> | 2012-09-14 11:35:43 +0000 |
|---|---|---|
| committer | Jean Delvare <khali@linux-fr.org> | 2012-09-14 11:35:43 +0000 |
| commit | f0af8775a1015a01c7eff9287f1442f5073ad8fa (patch) | |
| tree | 5b5782974c82f817a2400a6540a2363a41dbe4ac /doc | |
| parent | 4726e44ab8c105f57a30194d62099cdf6c0dc1ac (diff) | |
| download | lm-sensors-git-f0af8775a1015a01c7eff9287f1442f5073ad8fa.tar.gz | |
Update fan-divisors: fan divisors are optional, recent monitoring chips
don't have them so the document doesn't apply to these chips.
git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@6071 7894878c-1315-0410-8ee3-d5d059ff63e0
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/fan-divisors | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/doc/fan-divisors b/doc/fan-divisors index 4da50a4b..978f5a30 100644 --- a/doc/fan-divisors +++ b/doc/fan-divisors @@ -9,7 +9,39 @@ try the following: Look and see. Fans with tachometer outputs have at least 3 wires. Fans with only 2 wires cannot, in general, report their speed. -- Try experimenting with the fan divisor settings: +- If your monitoring chip supports fan divisors, try experimenting + with the fan divisor settings. + + +Does my monitoring chip use fan divisors? +----------------------------------------- + + Recent monitoring chips tend to store fan speed values on 12 or even + 16 bits, so divisors are no longer required. In that case, you won't + see "div" values in the output of sensors, and nothing needs to be + configured: + + CPU1 Fan: 2160 RPM (min = 800 RPM) + CPU2 Fan: 0 RPM (min = 799 RPM) ALARM + Front3 Fan: 0 RPM (min = 0 RPM) + Front4 Fan: 779 RPM (min = 600 RPM) + + If your "sensors" output looks like the above, stop reading here, + the explanations below do not apply to your case. + + Older chips stored the fan speed values on 8 bits, which wasn't + sufficient to cover the full range from very slow fans to very + fast fans with good accuracy. This is where fan divisors came + into play: + + Case Fan: 0 RPM (min = 998 RPM, div = 8) ALARM + CPU Fan: 2500 RPM (min = 1500 RPM, div = 4) + + If your "sensors" output looks like the above, read below. + + As a notable exception, the w83627ehf driver exposes fan divisor + values, but they are adjusted automatically by the driver, so you + shouldn't have to care. Fan Divisor Settings @@ -97,3 +129,4 @@ section of /etc/sensors3.conf: ------------------ Copyright (c) 2000-2004 Mark D. Studebaker +Copyright (c) 2006-2012 Jean Delvare |