Sleep! I have been able to get S3 sleep state working on the intel DG965SS, with WAKE-ON-LAN! For details, check out:

http://www.docunext.com/blog/2007/08/27/intel-dg965ss/

Power Measurements with a Celeron D

The intel DG965SS is averaging about 73 watts with a Celeron D installed in it.

# cat /proc/cpuinfo 
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 4
model name      : Intel(R) Celeron(R) CPU 2.66GHz
stepping        : 9
cpu MHz         : 2664.148
cache size      : 256 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 5
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 
clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc up pni monitor ds_cpl
tm2 cid cx16 xtpr lahf_lm
bogomips        : 5333.32
clflush size    : 64

I plan to try one of the newer Celeron chips that has a lower TPD. I've never been able to get voltage scaling to work on Celeron chips, but I have gotten the p4-clockmod module to work, which can reduce the frequency and heat of the chip.

Power with a Celeron 420

I changed this out to an intel Celeron 420, and the power was reduced to around 46 Watts.

$ cat /proc/cpuinfo 
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 22
model name      : Intel(R) Celeron(R) CPU          420  @ 1.60GHz
stepping        : 1
cpu MHz         : 1598.522
cache size      : 512 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 
clflush dts acpi mmx fxsr sse sse2 ss tm pbe nx lm constant_tsc up pni monitor ds_cpl tm2 
ssse3 cx16 xtpr lahf_lm
bogomips        : 3326.21
clflush size    : 64

I made some other changes, including the switch from a full size to a laptop hard drive, and the power is under 40, as low as 37 watts. Awesome.

Custom DSDT

# diff dsdt.dsl.orig dsdt.dsl
3340c3340
<                     0x04
---
>                     0x03