Power Efficient Computer for Helicopter Experiment

Folks,

I've got to deploy an experiment in a helicopter and the only electrical power will come from batteries. Therefore the computer needs to be very power efficient but not necessarily computationally powerful.

The motherboard must have at least a single PCI slot, on-board networking, and one SATA port. The requirement for the PCI slot is why I haven't just pulled a laptop mobo out of its case. The processor must be more powerful than an Atom - it's got to be fast enough to keep an SSD writing full-time. Ideally this is a micro-ATX board but I could live with a mini-ATX board. Cost isn't really that much of an issue (within reason).

Question: what motherboard / processor combination would you recommend? Keep in mind that I'm concerned with overall system power so the load of the motherboard's chipset must be factored into the equation. I'll also happily underclock or undervolt something if the stability is there.

Thanks.

Thanks, I'll look into both of those. -edited to remove my stupidity having now followed the links provided...

Thanks for the heads-up but we won't be using a hard drive in this - it'll be loaded with an SSD.

There's no display, keyboard, or mouse. The computer will boot up and automatically load the acquisition software and start taking data on the ground.

The power comes from Li-polymer batteries. I'd rather have a generator make power but that's not an option.

Turns out MSI makes a few socket P motherboards so I'll grab one of the newer 25W Intel processors for it.

Thanks for the input all.