Speeding up thermalization -- practical?
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From: GreenXenon on 25 Apr 2010 00:08 On Apr 15, 5:31 pm, whit3rd <whit...(a)gmail.com> wrote in http://groups.google.com/group/sci.electronics.design/msg/afed810b124c3b77 : > On Apr 15, 2:15 pm, GreenXenon <glucege...(a)gmail.com> wrote: > > > Can similar data recovery be performed on volatile RAM chips even > > after the power is offed. > > Similar, no. Recovery, yes. The volatility has a time decay constant > of a second or so, and it takes a long, temperature-dependent, delay > after power-off to thermalize the information to nonexistence. Let's say that after the power supply is cut-off from the volatile RAM chip, the RAM chip is heated to the hottest it can get without suffering any physical damage. Will this speed up the rate at which data is lost? What is the maximum physically-safe temperature to erase all info? What would be the best way of heating the chips?
From: mpm on 25 Apr 2010 13:14 On Apr 24, 11:08 pm, GreenXenon <glucege...(a)gmail.com> wrote: > On Apr 15, 5:31 pm, whit3rd <whit...(a)gmail.com> wrote inhttp://groups.google.com/group/sci.electronics.design/msg/afed810b124... > : > > > On Apr 15, 2:15 pm, GreenXenon <glucege...(a)gmail.com> wrote: > > > > Can similar data recovery be performed on volatile RAM chips even > > > after the power is offed. > > > Similar, no. Recovery, yes. The volatility has a time decay constant > > of a second or so, and it takes a long, temperature-dependent, delay > > after power-off to thermalize the information to nonexistence. > > Let's say that after the power supply is cut-off from the volatile RAM > chip, the RAM chip is heated to the hottest it can get without > suffering any physical damage. Will this speed up the rate at which > data is lost? What is the maximum physically-safe temperature to erase > all info? What would be the best way of heating the chips? I get your concept, but I'm pretty certain you are using the word "thermalization" incorrectly. The term has nothing to do with the termperature cycling of memory chips. It more correctly describes the process undergone by high-energy (fast) neutrons as they lose energy by collision. As to your question: I suspect there is no official answer to be found in the manufacturer's datasheets. Most likely, it will just specify absolute maximum limits and not guarantee any performance parameters beyond those ratings. Additionally, it will probably recommend that those limits not be approached in your design.
From: GreenXenon on 25 Apr 2010 15:45 On Apr 25, 10:14 am, mpm <mpmill...(a)aol.com> wrote: > On Apr 24, 11:08 pm, GreenXenon <glucege...(a)gmail.com> wrote: > > > > > On Apr 15, 5:31 pm, whit3rd <whit...(a)gmail.com> wrote inhttp://groups.google.com/group/sci.electronics.design/msg/afed810b124... > > : > > > > On Apr 15, 2:15 pm, GreenXenon <glucege...(a)gmail.com> wrote: > > > > > Can similar data recovery be performed on volatile RAM chips even > > > > after the power is offed. > > > > Similar, no. Recovery, yes. The volatility has a time decay constant > > > of a second or so, and it takes a long, temperature-dependent, delay > > > after power-off to thermalize the information to nonexistence. > > > Let's say that after the power supply is cut-off from the volatile RAM > > chip, the RAM chip is heated to the hottest it can get without > > suffering any physical damage. Will this speed up the rate at which > > data is lost? What is the maximum physically-safe temperature to erase > > all info? What would be the best way of heating the chips? > > I get your concept, but I'm pretty certain you are using the word > "thermalization" incorrectly. > The term has nothing to do with the termperature cycling of memory > chips. > It more correctly describes the process undergone by high-energy > (fast) neutrons as they lose energy by collision. > > As to your question: I suspect there is no official answer to be found > in the manufacturer's datasheets. > Most likely, it will just specify absolute maximum limits and not > guarantee any performance parameters beyond those ratings. > Additionally, it will probably recommend that those limits not be > approached in your design. I can think of 3 approaches to this problem of data retention in VRAM chips: 1. Low power induction heating 2. Low power microwaves 3. Low power lasers I say low power because the heat generated needs to be small enough not to damage the VRAM chip.
From: Robert Baer on 26 Apr 2010 03:44 GreenXenon wrote: > On Apr 15, 5:31 pm, whit3rd <whit...(a)gmail.com> wrote in > http://groups.google.com/group/sci.electronics.design/msg/afed810b124c3b77 > : > > >> On Apr 15, 2:15 pm, GreenXenon <glucege...(a)gmail.com> wrote: >> > > >>> Can similar data recovery be performed on volatile RAM chips even >>> after the power is offed. > > >> Similar, no. Recovery, yes. The volatility has a time decay constant >> of a second or so, and it takes a long, temperature-dependent, delay >> after power-off to thermalize the information to nonexistence. > > > Let's say that after the power supply is cut-off from the volatile RAM > chip, the RAM chip is heated to the hottest it can get without > suffering any physical damage. Will this speed up the rate at which > data is lost? What is the maximum physically-safe temperature to erase > all info? What would be the best way of heating the chips? Nominal MIL-spec temp range is -55C to +125C so one can safely use +125C for this operation. That said, most semiconductors easily tolerate 150C. Remember, ions, static charges, and chemical reactions speed up by a factor of two for every 10C increase in temperature.
From: John Larkin on 26 Apr 2010 11:15
On Mon, 26 Apr 2010 00:44:13 -0700, Robert Baer <robertbaer(a)localnet.com> wrote: >GreenXenon wrote: >> On Apr 15, 5:31 pm, whit3rd <whit...(a)gmail.com> wrote in >> http://groups.google.com/group/sci.electronics.design/msg/afed810b124c3b77 >> : >> >> >>> On Apr 15, 2:15 pm, GreenXenon <glucege...(a)gmail.com> wrote: >>> >> >> >>>> Can similar data recovery be performed on volatile RAM chips even >>>> after the power is offed. >> >> >>> Similar, no. Recovery, yes. The volatility has a time decay constant >>> of a second or so, and it takes a long, temperature-dependent, delay >>> after power-off to thermalize the information to nonexistence. >> >> >> Let's say that after the power supply is cut-off from the volatile RAM >> chip, the RAM chip is heated to the hottest it can get without >> suffering any physical damage. Will this speed up the rate at which >> data is lost? What is the maximum physically-safe temperature to erase >> all info? What would be the best way of heating the chips? > Nominal MIL-spec temp range is -55C to +125C so one can safely use >+125C for this operation. > That said, most semiconductors easily tolerate 150C. > Remember, ions, static charges, and chemical reactions speed up by a >factor of two for every 10C increase in temperature. Ions speed up? Static charges? Explain? John |