laptoptipsandtricks

PCI

This one will set all the devices without a loaded driver into sleep state.

hw.pci.do_power_nodriver=3

console

You can get full console resolution on an Intel 945-series graphics adapter with 915resolution. Find some spare mode like 640x480:

% sudo ./915resolution -l
Intel 800/900 Series VBIOS Hack : version 0.5.3

Chipset: 915GM
BIOS: TYPE 1
Mode Table Offset: $C0000 + $269
Mode Table Entries: 36
...
Mode 41 : 640x480, 16 bits/pixel
...

Set it to 1024x600 for example:

% sudo ./915resolution 41 1024 600

Then load vesa:

% kldload vesa

And use vidcontrol:

% vidcontrol -i mode|grep 1024
 257 (0x101) 0x0000000f G 1024x600x8 1    8x16  0xa0000 64k 64k 0xd0000000 7872k
 273 (0x111) 0x0000000f G 1024x600x16 1   8x16  0xa0000 64k 64k 0xd0000000 7872k
 274 (0x112) 0x0000000f G 1024x600x32 1   8x16  0xa0000 64k 64k 0xd0000000 7872k

% vidcontrol MODE_273

CPU

Allow cpu entering energy-saving state:

hw.acpi.cpu.cx_lowest=C3

Use est/powernow to control cpu frequency.