Jebe there isn't an SoC on this list that won't consume > 2W under heavy load, and the most power hungry ones there are all being put in phones. There are known cases of games draining phones with 8+Wh batteries in well under 2 hours.
Without a lot more information that doesn't really demonstrate anything to counter my point. LEDs are quite efficient in producing light from electricity, so while they do generate waste heat a good portion of their power consumption is being turned into light. The actual LCD part of an LCD should be similar. Speakers similarly will be have a significant amount of their power use turned into pressure waves, and antenna have a significant part of their power use turned into EM signals. All of which, as you know, contribute to power consumption in addition to the SoC.
If you have direct evidence of a phone being able to handle a sustained 2 Watt thermal load, and how they're making that work then go ahead and bring it forward. Or for that matter data on the Z3770 that isn't related to SDP which by Intel's own admission cannot be assumed to be where they set the TDP governor aka cTDP, let alone turbo throttling potential and should be assumed to be rated lower then both figures.
There also the issue that it's not uncommon to have metal cased phones like the iPhone 5S where case conduction turns the entire back of the phone into a heat spreader which also, like most Apple products, conducts heat to the user using them as a de facto heat sink. Needless to say double digit liters of blood plasma can handle 2 Watts with the very high specific heat associated with what makes up the majority of blood plasma. Their laptops however have some known issues with using that trick of using the user as a heat sink associated with the higher thermal load of those systems.
I doubt OpenPandora GmbH is in the position to be using precision milling machines with fancy aluminum case designs. If you want to bring some more specific examples where you can bring in the SoC power numbers then we can look at that. Otherwise thermodynamics isn't something where you can cheat the reaper so I'm not sure what you're trying to prove here.
A Pandora is better equipped to handle heat dissipation than a phone because its display isn't sandwiched against the rest of the thing.
The waste heat of the display should be relatively minor compared to the waste heat associated with discharging through a large battery. You're ignoring one of the biggest players while obsessing on something that's not necessarily even a major player. Heck it might actually be serving as a sink in some cases given how they're constructed normally, LED efficiency, and that they have a clean radiation window to the outside world.
Z3770 has a base speed of 1.46GHz. Passively cooled tablets can run all four cores at the max turbo of 2.4GHz for fairly lengthy periods of time.
This is where I have to ask what your reasoning is that this makes a meaningful case.
The Z3770 is basically designed for 10.1" tablets and when push comes to shove can be crammed into 8" systems. Using the iPad 4 as a reference it has a back which if flat would have an area that's 18 times my theoretical 5cm square wafer, which is large for a handheld, and has even more of an advantage as it's curved nature means there's even more area. Naturally with case conduction getting the heat to the outside and there being quite a number of grams of Aluminum involved meaning it also takes a while to raise the temperature significantly. To radiate 2 Watts of heat with even that flat back if my diseased state isn't making me mess things up should be possible at well below room temperature.
@ Jebe : You certainly seem to have a good grasp of thermal dynamics, if you could comment on the practicality of using no cooling solution for a current gen SOC in
this thread it would be much appreciated.
Could you explain a little more as to why in your opinion a passively cooled SOC would work fine in a tablet / phone but not in a handheld mini computer?
I'm sick right now, I'll look it over during the weekend. I don't necessarily agree the question is valid in the first place given there's not exactly a wealth of Tablets and Smart Phones demonstrating the ability to mach or outmuscle the Shield on a sustained basis rather then throttling in a short period of time, or anything else to substantiate the other inherent assumptions in that question.
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