CPU temp AC vs Battery

[Eric Anderson]

Hi everyone,

I've just noticed something very odd.  On my Dell D820 laptop, when 
running off AC power from boot, by idle CPU temperature sits around 58C.

If I unplug the power, and then plug it back in again, it will drop down 
to around 49-50C within a minute or two.  It will stay there.  With or 
without powerd running.

Here's some info:

# uname -a
FreeBSD 7.0-CURRENT FreeBSD 7.0-CURRENT #51: Tue Apr 24 10:24:43 CDT 
2007     snip at snip:/usr/obj/usr/src/sys/NEUTRINO  i386


# kldstat
Id Refs Address    Size     Name
  1   36 0xc0400000 77d33c   kernel
  2    3 0xc0b7e000 23398    linux.ko
  3    1 0xc0ba2000 118dc    snd_hda.ko
  4    2 0xc0bb4000 3c114    sound.ko
  5    1 0xc0bf1000 6d3e68   nvidia.ko
  6    1 0xc12c5000 4bb8     atapicam.ko
  7    6 0xc12ca000 c6d4     netgraph.ko
  8    1 0xc12d7000 79c8     ng_ubt.ko
  9    1 0xc12df000 5868     vkbd.ko
10    1 0xc12e5000 1d294    kqemu.ko
11    1 0xc1303000 2ffa4    ipl.ko
12    1 0xc1333000 13544    geom_journal.ko
13    1 0xc1347000 5d420    acpi.ko
14    1 0xc5b02000 6000     linprocfs.ko
15    1 0xc5b33000 e000     ext2fs.ko
16    4 0xc5d27000 2000     ng_bluetooth.ko
17    1 0xc5d29000 c000     ng_hci.ko
18    1 0xc5d35000 e000     ng_l2cap.ko
19    1 0xc5d43000 15000    ng_btsocket.ko
20    1 0xc5d61000 4000     ng_socket.ko
21    1 0xc5e4a000 7000     aio.ko

both before and after power plugging:
# sysctl dev.cpu
dev.cpu.0.%desc: ACPI CPU
dev.cpu.0.%driver: cpu
dev.cpu.0.%location: handle=\_PR_.CPU0
dev.cpu.0.%pnpinfo: _HID=none _UID=0
dev.cpu.0.%parent: acpi0
dev.cpu.0.freq: 1985
dev.cpu.0.freq_levels: 1985/-1 1736/-1 1488/-1 1240/-1 992/-1 744/-1 
496/-1 248/-1
dev.cpu.0.cx_supported: C1/1 C2/1 C3/57
dev.cpu.0.cx_lowest: C1
dev.cpu.0.cx_usage: 100.00% 0.00% 0.00%
dev.cpu.1.%desc: ACPI CPU
dev.cpu.1.%driver: cpu
dev.cpu.1.%location: handle=\_PR_.CPU1
dev.cpu.1.%pnpinfo: _HID=none _UID=0
dev.cpu.1.%parent: acpi0
dev.cpu.1.cx_supported: C1/1 C2/1 C3/57
dev.cpu.1.cx_lowest: C1
dev.cpu.1.cx_usage: 100.00% 0.00% 0.00%


Eric