Thread: My first project. All help wanted in all sections. Just need a few pointers :S

Originally Posted by jellymonster

Will this be ok for a micro-atx mothrboard

motherboard size is irrelevant. it's the hardware on/connected to the board that determines how much power is needed.

Originally Posted by jellymonster

Will this be ~ powerful enough to power my cpu, motherboard, hdd, dvd drive and 7" touch screen?

http://www.virtualvillage.co.uk/item...LAID=298049378

It's a 160W M2-ATX car psu

no, it will not be powerful enough. P4's are power-hungry processors (and generally are not a good choice for a carPC). the P4 630 alone can draw up to 7A from the 12v rail. a 3.5" HDD will draw up to 2A, monitor will draw about 1A from the 12v rail. the M2-ATX can only provide 8A max on the 12v rail (this is more than enough for most carPCs, but it's not powerful enough for the system you plan on building.

I'm not saying that you can't use the P4 system, but it will be more expensive due to the significantly higher cost of the higher power PSU. you won't be able to get away with the cheaper/smaller PSUs like the M2-ATX. it may be more cost effective to ditch the P4 setup and go with something much more efficient like the Intel Atom CPU/mobo.

Originally Posted by jellymonster

will drain my car battery?

there is no such thing as "too powerful" when it comes to PSU's. a PSU only provides as much power as the computer requires.

Originally Posted by jellymonster

will drain my car battery?

when your car is on, the alternator provides the power (not your car battery). your battery will only drain if you're using it with the engine off.

A few common misconceptions:

1 - SOME P4s are very power hungry. There are different cores for P4 CPUs. Some cores are higher power draw than other cores.

The P4 630 the OP specified is a Prescott 2 core that draws 84w max. That said, the power draw of that CPU alone would be pushing the limits of the M2ATX PSU you specified, but it would probably work, so long as you don't start pegging your CPU usage.
Honestly, I would go for a more powerful PSU to err on the side of reliability. You can't have a PSU that is too powerful, as FF said.


2 - When the car is on, the power is still coming from the battery. However, the alternator is also charging the battery at the same time, in most cases charging more than the power being drawn which leaves you with a fully charged battery when you shut off the engine.