Waaaaah!!! Do you really want to have a radiator in your device?
P4 - a so called high-frequency heating system!
I would better propose the xScale CPU because it consumes a power of less than 1 watt @1.5GHz and it has an internal 64 bit processing AND...it's totally a risc technology.

I would prefer have a small operating system like TOS with a spare but clear and definite desktop (like the K2k's display). This supports an easy and fast processing for musicians like me...

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Greetings from Frankfurt (Germany),
Sheriff ;-)