> > From: Jean-Francois [mailto:jfsimon1...@gmail.com]
> > Le lundi 08 fivrier 2010 04:10:22, Nick Holland a icrit :
> > With all this talk about power reduction...I'm going to toss out one
> > small suggestion:
> >
> > Get a Wattmeter, and measure... Don't waste your time speculating.
>
> Hello,
>
> I did. It's consuming some 90 Watts at idle.
> Actually, it's an Athlon but the latest Sempron has an even reduced TDP.
> My next server will be based on it.
> Actually even 70 Watts is a little bit high for my next server given the
> fact
> it will be in an autonomous environment (small wind/solar generators).
>
> Regards
Nick is right, numbers should speak.
Parameters at the time of measuring:
MB: GA-MA74GM-S2H rev1.x (no idea about TDP but according to [1] should be
low)
- unneeded MB components turned off, check my previous dmesg
- integrated GPU core slowed down from 400MHz to 200MHz
- Cool'n'quiet enabled in BIOS
CPU: AMD Sempron LE-1150 (TDP 45W)
- undervolted from 1.2V to 1.00V
- passive cooling
PSU: Enermax 400W Liberty (no data for this model but it's bigger brothers had
efficiency around 78% for 114W AC [2])
RAM: 1 stick of 1GB DDR2 800MHz
HDD: 3x 1TB, 2x 500G (4 Hitachi and 1 WD Green)
other: 1 low rpm 12cm system fan, no keyboard, no display
I measured my setup couple of times while setting it up. Numbers are from
memory, may not be accurate. Besides, I used a cheap powermeter, meaning the
absolute values are probably off but the deltas could be somewhat trusted:
1. On boot with everything on and no udervolting of CPU the AC wattage was
somewhere around 150W.
2. Undervolting the CPU to 1.00V and playing with the BIOS shaved off some
20-30W.
3. Setting the Hitachi drives to low power idle reduced the power draw for
another 20-30W, at the time the system was idling at 70-90W.
4. Putting the drives into sleep mode got the system under 70W. I'm not using
this atm, had some problems with long delays while waking up the drives.
All of that was without apm -C, basically the CPU was running at full speed.
For testing apm -C I was lazy and relied on temperatures.
1. Temperatures at idle with apm -C
hw.sensors.it0.temp0=28.00 degC
hw.sensors.it0.temp1=33.00 degC
2. Temperatures at idle with apm -H (from memory and different season)
hw.sensors.it0.temp0=34.00 degC
hw.sensors.it0.temp1=38.00 degC
Couple of degrees difference should mean at least couple of W difference.
Regards, Daniel.
Useful links:
47 watt 7 TB server (disks spun down) -
http://www.silentpcreview.com/forums/viewtopic.php?t=57476
TDP list for Intel chipsets -
http://www.silentpcreview.com/forums/viewtopic.php?t=35078
[1] http://www.silentpcreview.com/article859-page5.html
[2] http://www.silentpcreview.com/article279-page4.html
