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Half a century ago, neither Pentium 4 nor Athlon would go in flames without a cooler, but because they included thermal protection circuits that stop the clock

Half a century ago, neither Pentium 4 nor Athlon would go in flames without a cooler, but because they included thermal protection circuits that stop the clock above a certain temperature threshold, which cannot be modified by users. The halting of the clock is invisible for software, except that frequent and/or long clock haltings will lengthen accordingly the execution time of a long task that has spanned over time intervals when the clock has been stopped. The latest CPUs still include such a thermal protection, which is independent of the turbo clock frequency management, which is based on the power and current limits, which can be modified by the user, e.g. for overclocking. Older CPUs, until about the middle of the nineties, could be destroyed by inadequate cooling. This has forced both Intel and AMD to implement thermal protections, to avoid requests for CPU replacements.

kvemkon 1y ago
Perhaps, I've formulated not exact enough. I was remembering what has been demonstrated in the famous video [1] for Athlon 1400 and 1200. Yes, the went not in flame but just in smoke. Back then the user was allowed to install a cooler direct onto the die though AMD CPU had no thermal protection (just thermal diode for emergency power-off the whole system by BIOS?). I have no confirmation for the following but I've considered that the pre-installed and hard and risky to remove the pretty massive heatspreader plate works not only as die physical protection but also as a minimal needed buffer for heat dissipation in case of rapid cooler removal. [1] "What happens when the CPU cooler is removed?" (Tom's Hardware Guide, 2001) https://www.youtube.com/watch?v=y39D4529FM4 https://www.youtube.com/watch?v=y39D4529FM4 https://www.youtube.com/watch?v=UoXRHexGIok https://www.youtube.com/watch?v=UoXRHexGIok P.S. Another rather philosophical question I have since a ventilator (not just some heatspreader) was required for the first time for CPU to operate as advertised. Can one consider that CPUs are actually factory overclocked since then? Even though not to the absolute limit, e.g. Celeron 333A (@66) up to 500 (@100) manually.

kvemkon 1y ago

Perhaps, I've formulated not exact enough. I was remembering what has been demonstrated in the famous video [1] for Athlon 1400 and 1200. Yes, the went not in flame but just in smoke. Back then the user was allowed to install a cooler direct onto the die though AMD CPU had no thermal protection (just thermal diode for emergency power-off the whole system by BIOS?). I have no confirmation for the following but I've considered that the pre-installed and hard and risky to remove the pretty massive heatspreader plate works not only as die physical protection but also as a minimal needed buffer for heat dissipation in case of rapid cooler removal. [1] "What happens when the CPU cooler is removed?" (Tom's Hardware Guide, 2001) https://www.youtube.com/watch?v=y39D4529FM4 https://www.youtube.com/watch?v=y39D4529FM4 https://www.youtube.com/watch?v=UoXRHexGIok https://www.youtube.com/watch?v=UoXRHexGIok P.S. Another rather philosophical question I have since a ventilator (not just some heatspreader) was required for the first time for CPU to operate as advertised. Can one consider that CPUs are actually factory overclocked since then? Even though not to the absolute limit, e.g. Celeron 333A (@66) up to 500 (@100) manually.