[rescue] OT: *under* clocking & short rack mount

[Paul Sladen]

Hi gang... off topic, but probably the best place to get the knowledge
feedback!

I'm building a `Blackbox' for someone to measure the surface texture of a
pavements (Airports/Motorways)  whilst driving along in a Jeep at
30-50miles/hour.  Centre piece of this is an existing 20,000ukp laser
displacement meter, with rackmounts;  I am going to be building this into a
10U rack, along with a reduced Debian box for doing the datalogging.

Power:  There ain't much on a vehicle!  (and it needs an inverter).

Can I *under*clock a 500+Mhz Processor down to 150Mhz, and reap the reduced
power consumption?

Can I use an over-rated PSU (say 300+W), and reduce consumption too?

Lastly, anyone know short (depth) 2U ATX cases (<~450mm)  I need three PCI
slot for current and future datalogging.

Many thanks,
Paul

PS, anyone have particular favouriate 4x40 LCDs, or GPS recievers?