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This may be in the wrong section so if it is I apologize.

I'm trying to significantly reduce the temperature of my computer's RAM so I can preserve it's contents during a PC reboot. I read about the method in this paper.

While the RAM is still at about -50 degrees Celsius, is it okay to restart the computer? Will RAM function at that temperature? Or will the cold be electrically inhibiting it in some way?

Also, there's bound to be some spillover to other components of the liquid I'm using. I'm using those standard dust cleaner cans. Will this cause any problems? Also, will the RAM and computer components being wet with that liquid cause any problems?

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  • \$\begingroup\$ The contents of RAM are not modified by the act of rebooting. \$\endgroup\$ – Ignacio Vazquez-Abrams Aug 13 '14 at 23:45
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    \$\begingroup\$ @IgnacioVazquez-Abrams - the contents of DRAM do however rapidly start to become unreliable if refresh operations cease, which depending on implementation can be a consequence of rebooting. Cooling may well slow that process. \$\endgroup\$ – Chris Stratton Aug 14 '14 at 16:23
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You have other things to worry about other than the temperature dependance on leakage current. If you are dousing you board with refrigerant the cold surfaces will cause atmospheric moisture to condense out onto the surfaces which is generally not a good thing to be doing to your boards.

Whether or not this will retain your memory can only be known for that particular set of memories. I've had systems be reboot-able at room temperature and other systems not at cold temperatures. There are good chances that the memory will be retained given how conservative DRAM design is.

If you've solved the issue with your PCB becoming soaking wet and you don't exceed the temperature of the DRAM specifications (Which almost certainly is not -50 C ) then it should work. The operating temperature specification are given such that the timing specifications are met.

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  • \$\begingroup\$ The paper made it pretty clear that cooling the RAM would retain 99.9 percent of the memory intact. Is my PCB becoming soaking wet a major issue? Also, what you're saying is that my system may not even reboot at those temperatures? \$\endgroup\$ – Rayman Aug 14 '14 at 1:48
  • \$\begingroup\$ Yep, a wet PC board is a CONDUCTIVE PC board... and conductivity could do some serious damage in there. Parts of your motherboard carry +12V, while other parts contain TTL-LS and low-voltage CMOS circuitry that'll die suddenly if exposed to anything above about 3.3V. \$\endgroup\$ – TDHofstetter Aug 14 '14 at 3:16
  • \$\begingroup\$ @TDHofstetter Doesn't conductivity depend on the liquid used? Is the liquid I'm using (difluoroethane, which is standard dust cleaner fluid) conductive? \$\endgroup\$ – Rayman Aug 14 '14 at 3:54
  • \$\begingroup\$ It does - but remember that the sudden cold will condense considerable moisture (water) out of the air onto the PC board, which will itself carry some dust, making a conductive slurry. \$\endgroup\$ – TDHofstetter Aug 14 '14 at 4:02
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I think the greatest issue you'll face here is thermal shock - some of the stuff inside that computer case is running pretty hot, perhaps in the vicinity of 100*C (212*F). If it's suddenly shocked with -50C spray, it's very likely to crack from the thermal shock - its "first surface" will contract suddenly (thermal expansion coefficient) while everything behind that surface will still be fully expanded. If any of it cracks, that cracking will be relatively (small scale) violent, and will likely destroy that-which-was-hot-but-now-is-not.

What temperature is your memory at now? Will IT withstand a sudden drop to -50*C?

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