There's no gap in understanding, the only way a 400W laptop can be cool to the touch is if it rapidly dissipates all that thermal energy. That would require on

There's no gap in understanding, the only way a 400W laptop can be cool to the touch is if it rapidly dissipates all that thermal energy. That would require one hell of a fan, which is what I said with my hairdrier remark. Even 90W already requires a very noisy fan. A fan moving enough air to keep a 400W laptop cool to the touch isn't realistic to put into the form factor of a laptop, and a fan sufficient to keep even a 180W laptop cool seems extremely dubious to me. It would sound like a vacuum cleaner. What I was missing is the part where the laptop doesn't consume 180W and a substantial fraction of that power is just passing through the laptop to peripherals.