It's how much it's designed to dissipate right? Which depends on the cooling so by your meaning it's a vague number isn't it?
I think from power/watt number on a cpu people expect two thing. How efficient it is for the performance (electric bill) where you need input power. How better a cooling I need will need the thermal power.
But even with that the issue of Turbo makes it harder to quantify those two because it all depends on workload. If I recall correctly though even with all that if I understand correctly the peak power draw in intel gets throttled much easier than AMD whereas their TDP number (compared to AMD) artificially inflates their efficiency reputation. I do think they had been much more efficient than AMD specially pre Zen.
I think from power/watt number on a cpu people expect two thing. How efficient it is for the performance (electric bill) where you need input power. How better a cooling I need will need the thermal power.
But even with that the issue of Turbo makes it harder to quantify those two because it all depends on workload. If I recall correctly though even with all that if I understand correctly the peak power draw in intel gets throttled much easier than AMD whereas their TDP number (compared to AMD) artificially inflates their efficiency reputation. I do think they had been much more efficient than AMD specially pre Zen.