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> Why is it so important to make the chips smaller every time? Because the amount of power leakage (heat) is proportional to the size of the transistors. So yo

> Why is it so important to make the chips smaller every time? Because the amount of power leakage (heat) is proportional to the size of the transistors. So you cannot improve the efficiency of the chip without making the transistors smaller or lowering the frequency. > Obviously there would be downsides in cost of materials and power consumption, Huge costs. Data centers aren't only worried about the power consumption of chips, because for every watt that's generated as heat, they have to use >1W to cool that (because cooling systems aren't 100% efficient themselves). As you may know from other branches of science, the resistance of a conductor rises with heat, meaning that electrons running through the conductor are more likely to hit a vibrating atom and dissipate as heat. This is why so-called "super conductors" are usually super cooled. Very little atom movement = very low chance of an electron hitting a moving atom. Silicon is a semi-conductor, but the principal is the same. If the temperature of the chip rises, so does the heat generated. This is why world-record setting overclocks are done using liquid nitrogen to cool the chip. To prevent things from getting too toasty, data centers would have to reduce the density of the servers, which means they would need larger buildings and more land to house the same number of servers. > but wouldn't that be offset by avoiding the need for nano-manufacturing advances in every single round? In short, no.

williadc 10y ago
> the amount of power leakage (heat) is proportional to the size of the transistors Small correction: leakage actually increases as transistors shrink. This is why high-k dialectric and fin-fets were such important developments. They pushed back the point at which leakage power overtakes switching power as the dominant source of waste. Even with these technologies, we have to do a lot of design work to reduce leakage. I can't even guess how many power domains are on modern cpus -- certainly dozens if not hundreds. Most of those domains can be switched off to eliminate leakage in those domains altogether. I'm nearly certain you meant switching power reduces as transistors shrink, which has been true so far. Things are getting weird with these new processes, and a lot of things that we've held as fact are looking less and less reliable.
- kogepathic 10y ago
  > I'm nearly certain you meant switching power reduces as transistors shrink, which has been true so far. Yup. Thanks for the correction.
syngrog66 10y ago
well said! I had these as items 73, 75 and 76 in my cheatsheet for performance and scaling: http://synisma.neocities.org/perf_scale_cheatsheet.pdf
a_imho 10y ago
>Silicon is a semi-conductor, but the principal is the same. Afaik temperature dependence of materials is a more complicated relation than this. The graph of their coefficient does not even need to be monotone and can change depending on what properties dominate. E.g. a semiconductor can have NTC because charge concentration increases with the temperature, however when it reaches saturation this effect diminishes and it will behave similar to a regular PTC conductor. https://en.wikipedia.org/wiki/Temperature_coefficient#Negative_Temperature_Coefficient_of_Resistance_Of_a_Semiconductor https://en.wikipedia.org/wiki/Temperature_coefficient#Negati...
Dylan16807 10y ago
> Huge costs. Data centers aren't only worried about the power consumption of chips, because for every watt that's generated as heat, they have to use >1W to cool that (because cooling systems aren't 100% efficient themselves). Not at all. A typical cooling system might use 1 watt to move 4 watts of heat outside. And that's not really how superconductors work. That's how normal conductors work.
- kogepathic 10y ago
  > And that's not really how superconductors work. That's how normal conductors work. Can you name any super conductors which function at room temperature? I'm not aware of any. [1] [1] https://en.wikipedia.org/wiki/High-temperature_superconductivity https://en.wikipedia.org/wiki/High-temperature_superconducti...
  - Dylan16807 10y ago
    Your claim was "Very little atom movement = very low chance of an electron hitting a moving atom." That's something you get in a normal conductor. Low temperature, low resistance. A superconductor has no resistance. This is a very different thing. Completely different effects are taking over to make that happen.

williadc 10y ago

> the amount of power leakage (heat) is proportional to the size of the transistors Small correction: leakage actually increases as transistors shrink. This is why high-k dialectric and fin-fets were such important developments. They pushed back the point at which leakage power overtakes switching power as the dominant source of waste. Even with these technologies, we have to do a lot of design work to reduce leakage. I can't even guess how many power domains are on modern cpus -- certainly dozens if not hundreds. Most of those domains can be switched off to eliminate leakage in those domains altogether. I'm nearly certain you meant switching power reduces as transistors shrink, which has been true so far. Things are getting weird with these new processes, and a lot of things that we've held as fact are looking less and less reliable.

kogepathic 10y ago
> I'm nearly certain you meant switching power reduces as transistors shrink, which has been true so far. Yup. Thanks for the correction.

syngrog66 10y ago

well said! I had these as items 73, 75 and 76 in my cheatsheet for performance and scaling: http://synisma.neocities.org/perf_scale_cheatsheet.pdf

a_imho 10y ago

>Silicon is a semi-conductor, but the principal is the same. Afaik temperature dependence of materials is a more complicated relation than this. The graph of their coefficient does not even need to be monotone and can change depending on what properties dominate. E.g. a semiconductor can have NTC because charge concentration increases with the temperature, however when it reaches saturation this effect diminishes and it will behave similar to a regular PTC conductor. https://en.wikipedia.org/wiki/Temperature_coefficient#Negative_Temperature_Coefficient_of_Resistance_Of_a_Semiconductor https://en.wikipedia.org/wiki/Temperature_coefficient#Negati...

Dylan16807 10y ago

> Huge costs. Data centers aren't only worried about the power consumption of chips, because for every watt that's generated as heat, they have to use >1W to cool that (because cooling systems aren't 100% efficient themselves). Not at all. A typical cooling system might use 1 watt to move 4 watts of heat outside. And that's not really how superconductors work. That's how normal conductors work.

kogepathic 10y ago
> And that's not really how superconductors work. That's how normal conductors work. Can you name any super conductors which function at room temperature? I'm not aware of any. [1] [1] https://en.wikipedia.org/wiki/High-temperature_superconductivity https://en.wikipedia.org/wiki/High-temperature_superconducti...
- Dylan16807 10y ago
  Your claim was "Very little atom movement = very low chance of an electron hitting a moving atom." That's something you get in a normal conductor. Low temperature, low resistance. A superconductor has no resistance. This is a very different thing. Completely different effects are taking over to make that happen.