[mythtv-users] recommendation for new combined frontend+backend?
Michael T. Dean
mtdean at thirdcontact.com
Mon Oct 31 22:07:42 UTC 2011
On 10/31/2011 04:52 PM, Kris B. wrote:
> On Monday, October 31, 2011 8:41 PM, "Frank Hartmann" wrote:
>> In the past I did not let my system run always on, but let it manage
>> power-up and down itself by setting a bios timer. This way it runs only
>> for 2-3 hours a day. This was somewhat difficult to configure, but
>> worked quite ok for the past years.
> I have an older frontend with a normal power suppply. In the interest
> of cutting electricity, what I ended up doing is installing powernowd to
> scale the cpu frequency (down to .35 mhz for most of the time), reducing
> consumption that way.
While this is a good idea, when I started playing around with CPU
frequency scaling, I happened to notice that enabling CPU frequency
scaling did very little to alter power usage with my (AMD Athlon 64 X2
and AMD Athlon II) CPUs. At first, I thought this was a problem--then I
realized that the CPU at full frequency takes very little power when
idle. I was able to measure a very distinct increase in power usage
with my Kill-a-Watt when I actually maxed out the processor (about
25-40W depending on chip--where my chips are 65W TDP). But, IME, the
difference between the processor at full frequency while idle and the
processor at minimum frequency while idle is about 5W, max. Still
worthwhile, if frequency scaling is an option, but you're likely getting
good power savings when the processor is idle, either way.
Note that I didn't go to the trouble of attempting to measure difference
between maxed-out-at-minimum-frequency and
The only lesson I took from it is that idle (modern!) processors*** do
pretty well at saving power without any specific configuration.
*** Of course, this doesn't include "toys" where Intel, for example, cut
out all the idle-mode-power-saving capabilities to produce cheaper
silicon that runs at the same power usage when idle or when maxed out,
nor does it include old processors (such as AMD Athlon XP or Intel
Pentium 3/4 era ones).
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