Messages in this thread | | | Date | Mon, 25 Jul 2005 16:13:33 +0200 | From | Marc Ballarin <> | Subject | Power consumption HZ250 vs. HZ1000 |
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Hi, I did some measurements in order to compare power drain with HZ250 and HZ1000. To measure the actual drain, I used the "smart" battery's internal measurement. (Available with acpi-sbs in /proc/acpi/sbs/SBS0/SB0/state.) No clue how accurate this is.
Here some battery details, in case someone knows: charge reporting error: 25% SB specification: v1.1 (with PEC) manufacturer name: Panasonic manufacture date: 2004-11-27 device name: 02ZL device chemistry: Lion
Kernel: 2.6.13-rc3-mm1 + acpi-sbs
CPU: cpu family : 6 model : 13 model name : Intel(R) Pentium(R) M processor 1.60GHz stepping : 6
The "ondemand" governor was running, using acpi_cpufreq. (Idle at 600MHz).
Systems was running X11/KDE to get a more or less realistic scenario. No cron jobs, network traffic or additional applications. WLAN and built-in display were disabled completely, all fans and LEDs were off, internal hard disc was running. Additional peripherals: external keyboard, mouse, display and externally-powered hard disk (USB).
The results are quite simple: In both configurations the current settles between 727-729 mA (Voltage ~16.5 V).
Some issues:
- C-states look strange: active state: C2 max_cstate: C8 bus master activity: 00887fff states: C1: type[C1] promotion[C2] demotion[--] latency[000] usage[00000010] *C2: type[C2] promotion[C3] demotion[C1] latency[001] usage[01367471] C3: type[C3] promotion[--] demotion[C2] latency[085] usage[00000000]
- I don't know, how much polling of the battery affects results. Reads always block for ~10 seconds, and I used this behaviour for rate-limiting.
- Is this approach valid at all?
- I could repeat the test in single user mode with internal hard disc turned off.
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