Archived posting to the Leica Users Group, 2010/07/16

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Subject: [Leica] CPU power vs. battery life
From: lrzeitlin at (Lawrence Zeitlin)
Date: Fri, 16 Jul 2010 15:59:12 -0400

Akhil asks:

Can any list members shed some light on the CPU power vs. battery run-time

trade offs involved? I have of course, asked the manufacturers' tech support

but never could get a satisfactory answer.

- - - - -

First be aware that all computer manufacturers lie about battery run time. A
good rule of thumb is that, in normal use, you will get no more than half
the battery run time claimed.

Second, CPU cycles take power. The faster the CPU, all other things being
equal, the less the battery run time. Just how much shorter depends on a
variety of other factors like screen brightness, disc run time, Wi-Fi use,

For portable use manufacturers favor chips with conservative power
requirements rather than faster, more capable power hogs.

Most laptop makers have a minimum battery use mode for extended portable
operation. If you look at just what the computer does, you invariably see
that the CPU speed is reduced, sometimes to half its normal setting, the
disc run times shortened, and the screen turned off after several minutes
without keystrokes.

My experience with battery operated computers ranging from the old HP LX 100
handhelds to the latest MacBooks is that the lower the CPU power, the longer
the battery life. There ain't no free lunch.

Larry Z

Replies: Reply from ricc at (Ric Carter) ([Leica] CPU power vs. battery life)