Have you ever bled from a burn? If yes, you should see a doctor. Oo
Nobody said anything about denaturing protein. The aluminum back's temperature increases. It interfaces with hands. From a materials perspective a hand is a bag full of circulating fluid (blood). Blood will move the heat away from the hands - and thus away from the aluminum. No crispy flesh or bleeding out needed for this example.
If something "feels hot", what you're actually sensing is the transfer of heat from the object. Cold does not exist. Cold is our perception of a device or object that has less heat or more capacity for additional heat than the relative perspective of the measuring person or device. Even a Bose-Einstein condensate at so close to 0K that atomic structure collapses does not, "have cold". It simply has less heat.
Air conditioners do not produce cold. They capture heat from one place, transport it to another then shed it (and the heat of operation) to the 2nd environment.
ED & Exophase are oth on the right track about a heat sink only haing a set capacity before it looses effectiveness unless the heat is then somehow transported away. We call this movement of heat, "Heat Exchange". The device used is a "Heat Exchanger". A solid to ambient air heat exchanger is often called a radiator.
The GPD Win solution here is to make it's heat exchanger more efficient at transporting heat from the device materials to the surrounding air by moving more air past the hot parts (radiator) via convection (moving air). The aluminum back also allows for some heat to be transported from the device to the person using it via conduction (touch) to an object (hand) with circulating fluid (blood). The aluminum back is then a heat sink (mass of aluminum) that also acts as a conduction heat exchanger (touching a surface with less heat). Their intent appears to be to allow more compute cycles prior to throttling or a higher average cycle rate at equilibrium.
The Pyra solution as I understand it is to absorb short spike-loads in heat via a heat sink (chunk of metal) and dissipate system heat load relatively slowly through the plastics to the surface it is sitting on or to the user. Pollycarbonate is a good insulator - which might not be ideal. This is the reason for my posts in other threads here about ideas for options in case the internal components generate more heat than the device can shed through it's pollycarbonate shell.
The net, though, is that a device like these either needs to shed heat or lower heat generation or melt. The heat has to go somewhere, stop being generated or allowed to build. I hope that the transmission through the pollycarbonate shell to the surrounding air/desk/hands is adequate to maintain enough headroom to do the processing that the unit is supposed to do.
All of that out of the way... I have an idea - IF heat is an issue. For a 'gamer optimized' version of the Pyra, nix the 4G radio & antenna and put in a tiny fan to move air ducted from the SoC out a vent hole. It could maintain a higher clock for a longer time at the expense of battery life and loosing the 4G capabilities. The power lead circuits for the mobile module could then be repurposed into power for the fan in this scenario.
Personally, I still want mine with the 4G.
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Since heat goes upwards, should't the cooling metal case part actualy be sitting on the top side of the base instead of the bottom?
Hot air rises - that is a fact. BUT - it doesn't rise because it is hot. It rises because it decreases in relative density.
For gases, PV=nRT.
For a given number of molecules (n) of gas, if the temperature (T) increases, one or both of the pressure (P) and/or volume (V) must increase proportionally. In open atmosphere, the pressure (P) is a relative constant. So, as the volume (V) expands and the mass/molecules (n) remain constant, it's density (mass per cubic unit) decreases and the warmer, less dense, gas will rise while cooler more dense gas flows in around it to replace it. With a continued source of heat the cycle can repeat or be continuous. This is heat driven convection.
Within a solid object, heat will travel down at pretty much the same speed as it will travel up or sideways. It can actually be measured in it's advancement through solid objects with a common unit being W/mK
http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html
Silica Aerogel ~ 0.02
Wool blankes score ~ 0.04
Polycarbonate transports heat through itself at 0.19 W/mK
Steel is ~ 43
Aluminum is ~ 200
Copper is ~ 370
Silver is ~ 429
Diamond is ~ 1000
Annectdotally, heat moves through butter and coal at roughly the same rate as polycarbonate. Butter simply has a lower melting point and it can be notoriously difficult to get a fire hot enough to push enough heat in to ignite Anthracite coal. The point is, though materials may have similar heat transfer properties there are are other properties that make them better or worse at specific applications.
'nuff physics for one day.
