what kind of battery are u using? what psu?
because you can leave a car on s3 sleep a lot longer than you might think. Mine is setup for voltage instead of a timer, so if my battery's voltage drop below 12.3V (or whatever i like) the psu will hard shutdown. And I've left my car for 2 - 3 days without hard shutdown happening.
I drive my car everyday so it has to stay on s3 at least 12h/day which has never been a problem.
What about ASUS AT3N7A-I? Dual-core 1.6Ghz atom, pci slot, 8+2 USB, VGA, HDMI, 7.1 analog/digital,
NVIDIA ION GeForce 9300
Audison VRX 2.400(2x250WRMS at 4Ohm and 12.6V)
Audison VRX 4.300(4x110WRMS at 4Ohm and 12.6V)
Audison VRX 1.500(1x2000WRMS at 1Ohm and 13,8V)
All 3 amplifiers are AB class. Reason why I don't want leave it more than 2h in S3 is that I don't want to much empty battery which can effect on my audio system...
Although I do question why you say the cpu isn't powerful enough? An 8400 is a pretty good everyday processor, what are you doing on a carpc to use it up?
I like the Zotac boards, I've done two builds for people with them and had no problems. Great bang for buck feature wise, and I didn't have any driver problems. I used the mini-itx 9300 though.
A quick power search on newegg reveals nothing, although they don't carry much in the ways of mini-itx. A good 75 results in matx tho. http://www.mini-itx.com/store/?c=49 <- that is a 775 socket mini itx with a pci slot, you will have to read through for the other features... Its an Intel DG41MJ.
You need a real-time OS. The NT Kernel's scheduler just doesn't give a big enough time slice to mission-critical apps like audio processing. If you are really serious about doing audio processing, run Mac OSX or Linux. Getting bigger faster hardware is just a band-aid.
This CPU can handle Phase Linear filter's but can't Fir-Min.
I run for each channel Phase Linear crossover, Phase Linear EQ, Phase shift(on one channel is 180° on others is 0°) and one instance TimeDelay.
So currently runing:
5xElectri-q VST plugins(Phase Linear)
3xPhase PhaseBug VST plugins
1xVoxengo Sound Delay
So when I will switch to 4Way I will run:
7xElectri-q VST plugins(Phase Linear)
4xPhase PhaseBug VST plugins
1xVoxengo Sound Delay
But I would like try to use Fir-Min mode in Electri-q which is now on imposible... Also I will run CAN plugin for my new digital dashboard, which for gauges need a lot of CPU power...
but now we are to way offtopic...
Lets focus on fast POSt motherboards, WITHOUT sharing PCI resources without other devices...
Do you compete your car in audio contests?