3 ms·

I'd imagine integrated channels for liquid or evaporative cooling would work quite well. Something like a 100 micron diameter tube every square mm or so is in

I'd imagine integrated channels for liquid or evaporative cooling would work quite well. Something like a 100 micron diameter tube every square mm or so is in principle totally doable. Obviously a non-trivial engineering challenge but nothing breaking the laws of physics.

AstralStorm 8y ago
No they don't. You cannot circulate fluid at micrometer spaces at speed - huge forces are required. (Try it at home, push two panes of glass together and try to push water through. Good luck. You'd crack the glass first and silicone is even less resilient...) Capillary action works but it is too slow to make a dent in cooling. Heatpipes need like a few milimeters of such micrometer fabric to work reasonably well. Even solid metal mesh is not good enough at the available thickness. (And its capacitance will pose a problem.) You'd have more luck integrating power hungry thermoelectric components to push heat at huge power cost... (since you will be using exotic materials soon anyway)
- thereisnospork 8y ago
  You vastly overestimate the forces required. Pumping water, let alone a less viscous organic fluid at a few mLs per minute through nominally 100micron pipe is fairly routine. You wouldn't even need 100psi to move a few mL/tube: plenty to absorb the heat output from a fraction of a processor layer.
  - AstralStorm 8y ago
    Few mL/min is not enough cooling, that's the point. Way not enough to make a dent. Vapour phase is used in GPU interface already and is comparable to solid copper but lighter, why do you think merging a heatsink with the CPU will work when Intel has trouble even soldering the devices and leaves thick silicone layer on top? We're talking about something to remove many watts. This means huge capillary volume to compensate for low flow. Which means a lot of heatpipe surface soldered somehow to IHS. You'd have more success with solid copper layer which is sort of done where possible. (It's often not due to inductance.)
    - thereisnospork 8y ago
      math: 200W output per CPU 'layer' on a 17x17mm* die = 17 x 127micron tubes flowing 25mL/min each at 160psi (easily reducible with moderately larger capillaries) totals 425mL/min. 425mL/min of water starting at 30C and ending at 75C would absorb 45C * 425mL/min 4.16J/C = 79,560 J/minutes or 1,300 watts - about 600% of requisite cooling capacity. nominal threadripper #'s http://www.waters.com/webassets/other/lp/prep_calc/Tubingandsplitters/Tubingandsplitters.htm?locale=en_US http://www.waters.com/webassets/other/lp/prep_calc/Tubingand...

AstralStorm 8y ago

No they don't. You cannot circulate fluid at micrometer spaces at speed - huge forces are required. (Try it at home, push two panes of glass together and try to push water through. Good luck. You'd crack the glass first and silicone is even less resilient...) Capillary action works but it is too slow to make a dent in cooling. Heatpipes need like a few milimeters of such micrometer fabric to work reasonably well. Even solid metal mesh is not good enough at the available thickness. (And its capacitance will pose a problem.) You'd have more luck integrating power hungry thermoelectric components to push heat at huge power cost... (since you will be using exotic materials soon anyway)

thereisnospork 8y ago
You vastly overestimate the forces required. Pumping water, let alone a less viscous organic fluid at a few mLs per minute through nominally 100micron pipe is fairly routine. You wouldn't even need 100psi to move a few mL/tube: plenty to absorb the heat output from a fraction of a processor layer.
- AstralStorm 8y ago
  Few mL/min is not enough cooling, that's the point. Way not enough to make a dent. Vapour phase is used in GPU interface already and is comparable to solid copper but lighter, why do you think merging a heatsink with the CPU will work when Intel has trouble even soldering the devices and leaves thick silicone layer on top? We're talking about something to remove many watts. This means huge capillary volume to compensate for low flow. Which means a lot of heatpipe surface soldered somehow to IHS. You'd have more success with solid copper layer which is sort of done where possible. (It's often not due to inductance.)
  - thereisnospork 8y ago
    math: 200W output per CPU 'layer' on a 17x17mm* die = 17 x 127micron tubes flowing 25mL/min each at 160psi (easily reducible with moderately larger capillaries) totals 425mL/min. 425mL/min of water starting at 30C and ending at 75C would absorb 45C * 425mL/min 4.16J/C = 79,560 J/minutes or 1,300 watts - about 600% of requisite cooling capacity. nominal threadripper #'s http://www.waters.com/webassets/other/lp/prep_calc/Tubingandsplitters/Tubingandsplitters.htm?locale=en_US http://www.waters.com/webassets/other/lp/prep_calc/Tubingand...