[citation][nom]TheZoolooMaster[/nom]This sounds a lot like the 3D microchips that Kurzweil said would be the next step in sticking true to Moore's law.[/citation]
I am 100% with you! It's been a long time coming, but Kurzweil was one of the first to say that is was not only possible, but necessary. Can't wait to see it happen![citation][nom]elcentral[/nom]so twice the power twice the heat.[/citation]
actually no. Twice the heat dissipation issue would not be cumulative, it would be exponential. The top core would stay plenty cool, but the bottom or middle cores would be insulated AND have active heat sources around them. This means heat issues in the 3-10 fold range, not a mere doubling.
[citation][nom]Dangi[/nom]Heat may no be a real problem, IBM some time ago design a new system to cool chips by creating nanotubes inside the cheap and running water throught it[/citation]
That is exactly what the article proposes.
[citation][nom]frombehind[/nom]so if ivy bridge has major heat woes with side-by-side cores... how is stacking them like hotcakes (pun inteded xD ) going to make them generate LESS heat?[/citation]
IB does not have a heat issue. At stock voltages it runs as cool or cooler than SB, while having a ~5% performance increase. The heat issues arrise when OCing the chips, which is quite frankly not a problem for 99% of the world. IB does not have a heat issue, it has a OC issue, and it is due to the new die process, and 3D gates, and as these new processes mature and we can lower the voltage on chips of this size then it will become less of an issue.
[citation][nom]spp85[/nom]Stacking Processor Cores is a good idea, but how they cool the lowest cores ? Heat dissipation would be the biggest problem...[/citation]
That is the several billion $$ question, and there are several ways to do this.
1) turbo boost the top core for best single core performance, and then have TONS of smaller cores throughout the rest of the chip. So instead of having architecture akin to what we are use to with 2-8 traditional cores which can each do anything, we would see something more like the Cell processor with 1 'command' core, followed by a bunch of either specialized cores, or even more homogeneous cores that are more similar to an ARM architecture.
2) You can have a fair amount of physical distance between layers, and still have an advantage over a flat chip for signal processing. Thermal pipes or vents could still be crammed between layers for heat dissipation. Joytech22 mentioned the idea of changing the heat sink contact from the top only, to being on the top and edges. I would submit an idea of putting the pin-outs on the edges and having heat spreaders on what has traditionally been the top and bottom.
3) Engineers ultimately need lithography and design tools that allow them to get away from 2D chip design. The real advantage to 3D chips is not in layering cores on top of each other, but making each core a 3D structure so that the inputs and outputs of individual processing 'routes' are closer together, and then making the physical distance of these 'routes' shorter. Less distance, means less resistance, means lower voltage, means less amperage, means less heat. These also mean less latency and faster processing time for instructions (and also less material used). However, this is still in the science fiction realm as the tools to do it are not really available yet, but this is the direction we will have to take in time.
4) The material we are using for chips today (silicon) is not the best at heat dispersal, it was merely readily available at the time, and we have a whole eco system built around it which helps keep the cost down. Moving to other materials (graphene, molybdenite, even diamond) will go a long way towards better heat dispersal. Silicone is a heat insulator. Moving to something that conducts heat without a large amount of electricity would allow for much better cooling. Even more interesting is the idea of having the chip made out of a conductive material, and then insulating the routes. IBM has already done this with a copper processor ~20 years ago. It was just a research project to see if it could be done, but was not seriously pursued because it was not practical. Still, it is just one of many ideas of how to make 'cooler' chips that could be stacked.
5) Stacking everything in layers is not necessarily the best design. In a 3D space where heat is of concern a better approach may be more of a radial hub and spoke aproach, or constructing a chip with a backplane and fins like we do in our computer with a motherboard and daughter cards (a backplane controller and connector interface with specialty processors at right angles to it). Imagine the control unit (with integrated northbridge and cache... because lets face it, the north-bridge is going to disappear soon) on the back-plane, and then having processing cores perpendicular to it, or radiating outwards from it.
6) moving away from electrical processors and moving towards light based processing. Very cool, less heat, less power, and super awesome (aka, I have no idea how it works 😛 )
anywho, sorry for rambling. This is something I have dreamed about sense I was a kid, and it is super exciting to see it start to come into reality! It will be very interesting to see what comes out of the market to solve these interesting space and heat issues. So exciting!