Bear in mind that I'm too busy at the moment to do any research, and I have no experience or knowledge with either of these processor lines.

With that said, I'd pick the P4. The Athlon desktop processors have long kept up with Intel's offerings, but at the expense of greater power requirements and more heat dissipation. I can't see that they could have engineered the processor down to a laptop level without sacrificing a significant amount of its computing capability.

P4m's, on the other hand, don't sip much power at all, run cooler, have auto-throttling mechanisms in place to ensure safe operating temperatures, and they're not that sluggish either.

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