4 ms·

The biggest problem with 3d chips is the heat from the logic die down below. It might not be an issue when the logic is simple and doesn't do a lot. But once y

by petra 10y ago

The biggest problem with 3d chips is the heat from the logic die down below. It might not be an issue when the logic is simple and doesn't do a lot. But once you want to put complex and fast logic there, it's a big issue, the same issue preventing putting memory on top of the CPU. So it would be interesting to see how they would approach this.

akkartik 10y ago
Fascinating. Your comment got me to go googling for research on heat dissipation in 3D chips. A few links: http://www.electronics-cooling.com/2013/03/measured-thermal-resistance-of-microbumps-in-3d-chip-stacks http://www.electronics-cooling.com/2013/03/measured-thermal-... which evaluates an approach of positioning wiring and soldering in each layer so they transmit heat vertically up to the heat sink. http://www.nature.com/news/computer-engineering-feeling-the-heat-1.11993 http://www.nature.com/news/computer-engineering-feeling-the-..., which mentions among other things microfluidics where fluid flows through microscopic channels etched into the silicon. Another great quote: "In a computer, as much as 96% of the machine's volume is used to transport heat, 1% is used for communication (transporting information) and just one-millionth of one per cent is used for transistors and other logic devices. By contrast, the brain uses only 10% of its volume for energy supply and thermal transport, 70% for communication and 20% for computation." http://www.sematech.org/meetings/archives/3d/8334/pres/Fukushima.pdf http://www.sematech.org/meetings/archives/3d/8334/pres/Fukus... has some neat pictures of simulated heat maps. http://www.me.gatech.edu/featured_3Dchipcoolingtech http://www.me.gatech.edu/featured_3Dchipcoolingtech mentions a DARPA effort to fund research into 3D chip-cooling technology.
amelius 10y ago
One important aspect of memory is that you don't access all of it all the time. So I'm not sure if heat is such a problem here.
- AstralStorm 10y ago
  So it would make sense to put it on the bottom layer, not the top.
Razengan 10y ago
Would designing chips like a Menger sponge help with the heat issues? http://en.wikipedia.org/wiki/Menger_sponge http://en.wikipedia.org/wiki/Menger_sponge
agumonkey 10y ago
I'd say intermediate lanes to convey heat outside of the vertical line where surface can help dissipate. An intraprocessoral matrix to sound biological.

by petra 10y ago

akkartik 10y ago

Fascinating. Your comment got me to go googling for research on heat dissipation in 3D chips. A few links: http://www.electronics-cooling.com/2013/03/measured-thermal-resistance-of-microbumps-in-3d-chip-stacks http://www.electronics-cooling.com/2013/03/measured-thermal-... which evaluates an approach of positioning wiring and soldering in each layer so they transmit heat vertically up to the heat sink. http://www.nature.com/news/computer-engineering-feeling-the-heat-1.11993 http://www.nature.com/news/computer-engineering-feeling-the-..., which mentions among other things microfluidics where fluid flows through microscopic channels etched into the silicon. Another great quote: "In a computer, as much as 96% of the machine's volume is used to transport heat, 1% is used for communication (transporting information) and just one-millionth of one per cent is used for transistors and other logic devices. By contrast, the brain uses only 10% of its volume for energy supply and thermal transport, 70% for communication and 20% for computation." http://www.sematech.org/meetings/archives/3d/8334/pres/Fukushima.pdf http://www.sematech.org/meetings/archives/3d/8334/pres/Fukus... has some neat pictures of simulated heat maps. http://www.me.gatech.edu/featured_3Dchipcoolingtech http://www.me.gatech.edu/featured_3Dchipcoolingtech mentions a DARPA effort to fund research into 3D chip-cooling technology.

amelius 10y ago

One important aspect of memory is that you don't access all of it all the time. So I'm not sure if heat is such a problem here.

AstralStorm 10y ago
So it would make sense to put it on the bottom layer, not the top.

Razengan 10y ago

Would designing chips like a Menger sponge help with the heat issues? http://en.wikipedia.org/wiki/Menger_sponge http://en.wikipedia.org/wiki/Menger_sponge

agumonkey 10y ago

I'd say intermediate lanes to convey heat outside of the vertical line where surface can help dissipate. An intraprocessoral matrix to sound biological.