Re: [Bltk-discussion] How to Compute [watts] and what are the units ofP/C states?

[Lebedev, V. P <vla...@in...>]

Hi,

> I used bltk to test 2 batteries one is 3months age and another one
24months age.=20

            First of all please send compressed result directories of
both cases.

=20

Vladimir.

=20

________________________________

From: blt...@li...
[mailto:blt...@li...] On Behalf Of
Thitinan Tantidham
Sent: Tuesday, December 19, 2006 9:31 PM
To: blt...@li...
Subject: [Bltk-discussion] How to Compute [watts] and what are the units
ofP/C states?

=20

Hello Everybody,

=20

My CPU, AMD Athlon XP 1600+, from/proc/acpi/battery/BAT0/info it shows

design capacity: 4016 mAh

last full capacity: 4011 mAh

design voltage: 9600 mV

=20

I used bltk to test 2 batteries one is 3months age and another one
24months age.=20

With the same profiles, of course the battery lifetime from 2 batteries
come out different.=20

If I take this formula as following to calculate watts:=20

=20

Power (watts) * t =3D V * (At)

Power (watts) =3D V * (At) / t

=20

In my case V=3D9600mVolts =3D 9.6Volts (from ACPI gives constant calue),
(At)=3D4011mAh=3D4.011Ah

For idle profile:

the old battery:  t(o)=3D49min=3D0.82h, Power (o) =3D 46.96Watts

the new one: t(n)=3D207min=3D3.45h, Power(n) =3D 11.16Watts

=20

Questions:

1. Does it make sense that different batteries (on the same platform,
same profile) give different power?=20

If not, what parameters should be the factor to compute watts, if
voltage is constant?=20

Which formula can we use to compute power?=20

=20

2. What are the units of C-state and P-state? Hz or sec?

In my case (AMD Athlon XP 1600+) gives C1, C2 and P0, P1, P2, P3, P4 for
C-State and P-State respectively. From one line of idle profile shows
C1=3D1890, C2=3D16361,,P0=3DP1=3DP2=3DP3=3D0, P4=3D5961, for the =
summation of P-state
is approximately 6000. =20

=20

Thank you very much for your help.

Best Regards,

Thitinan


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