Paying Attention To CPU Thermal Specifications

I recently lost a web server due to overheating. While it’s not clear yet as to what, if anything, survived, a little research into the matter revealed something startling.

I used to keep all my servers in the attic. Being an unventilated attic, I used an air conditioner with a thermostat set to 85°F (29°C) to attempt to keep temperatures down while balancing costs. I say attempt because, using a remote digital thermostat to keep tabs, room temperatures hovered around 90°F (32°C) during the hottest days.

My old file, web, and database servers operated with Intel Pentium II 266MHz, 333MHz, and 350MHz processors, respectively. When I decided to get a file server capable of gigabit ethernet and a new dual-core desktop, the file server moved to an AMD Athlon 64 3000+ and the web server and databased server were merged into one and run on the old AMD Athlon XP 2200+ desktop.

While I did not believe the file server would last day one in the attic, for whatever reason I thought it was OK to leave the web/database server in the attic.

AMD Athlon 64 3000+ 1.8GHz 67W 65°C (149°F)
AMD Athlon XP 2200+ 1.9GHz 68W 85°C (185°F)
Intel Pentium II 350 MHz 22W 75°C (167°F)
Intel Pentium II 333 MHz 24W 75°C (167°F)
Intel Pentium II 266 MHz 20W 75°C (167°F)

Well, I was right on the file-server front because it turns out that the AMD Athlon 64 3000+ has the lowest max CPU temperature of them all. Keeping in mind that a CPU heat sink can only cool a processor down to room temperature, this puts the Athlon 64 3000+ squarely in the danger zone of unventilated and unconditioned attics, which can reach temperatures of 65.5°C(150°F).

On the web-server front I was not so lucky. While the Athlon XP 2200+ only consumed 1 more watt max than the Athlon 64 3000+, temperature wiggle-room bumped up a whopping 20°C (36°F). But with frequent (twice-a-month) 2-second black-outs during the summer and an air conditioner that stays off after the power goes out, the processor didn’t stand a chance.

These blackouts have always been a problem in my neighborhood during the summer, but no one really notices or cares because they’re either not home, asleep at home, or don’t have something critical requiring constant power. So how did the old servers survive under similar conditions? Quite simply, while the temperature requirements were 12% tighter, the power consumed by the old processors was a whopping 68% less. Less power means less heat to dissipate.

So I’m stuck with a computer that will not boot. I’ve already tested and verified that the power supply unit is OK. The only things left are memory, CPU, and motherboard, but there is no use testing these parts. The memory is DDR1, the motherboard is a deprecated Socket A, and CPU switching is dangerous in that a faulty CPU can ruin a motherboard (and vice versa).

I’ve already ordered parts to re-build the web/database server, which I’ll talk about in another article. Having a multiple computers within my vicinity, quietness is top-priority.