[ltp] IBM R51: The always on fan problem

[Paul RIVIER]

hello there,

Hunter Fuller wrote:

>
>
>>
>>
>> Apart from the frequency all CPUs can enter sleep-stats (called C1,  
>> C2,...C8, C1 = almost no power saving, C8 = a lot of power saving)  
>> to save power. If you enable/load the Xserver extentsion GLX the  CPU 
>> can no longer enter stats below C1. So far i don't know why.  With 
>> all after drivers loaded it reaches C3. With a bit hacking you  can 
>> get C4 (IMHO not worth it).
>
> On mine with GLX on and off I get the same results.

Many factors can prevent cpu to enter in Cx state. It has been observed 
on certain configurations that GLX is one of them.

>>
>> Next problem is the WLAN-card. In default configuration it get's  hot 
>> quite fast. If you enable "Power Management" (see iwconfig) it  
>> consumes a lot less energy.
>
> Huh? The WLAN card triggering the fan?! My touchpad doesn't feel hot  
> (and it's directly under the touchpad).

Intel centrino WLAN consumption is between 2W and 3W. It is a lot. That 
is why there is a throttling technology associated with it.

>>
>> If you want more: undervolt the cpu.
>
> Ew! I'd rather run Windows than risk my hardware. And I don't like  
> Windows much.

So far, 0 hardware failure due to undervolting has been reported, at 
least on forums I read.

Here:
T42 pentium M 1.7 Ghz
512 Mo ram
xorg radeon driver /w DynamicClock
wlan power management
undervolting
=> 10.5W when idle.

Same with no dynamicClock nor undervolting nor wlan power management : 
17W when idle.

>>
>> cu
>> -- 
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>