The Same Ol' Topic: Protection Against An AMD Thermal Death
Approximately nine months ago, THG stirred up quite a commotion with its article Hot Spot: How Modern Processors Cope With Heat Emergencies . Accompanying the article was our very first downloadable video, which shows the dramatic behavior of an AMD Athlon with a Palomino core, equipped with a thermal diode, when the CPU cooler fails during operation.
The alarms sounded at AMD, and the THG crew met several times with engineers from the manufacturers in question (AMD and Siemens). A few weeks later, AMD introduced a new circuitry logic to a small group of people. This was supposed to turn off the power supply as soon as the die temperature surpassed 85 degrees Celsius.
In order to guarantee faultless protection, the CPU temperature is measured by the thermal diode in very short time intervals, which ensures that the power can be switched off in time. Currently, all motherboard makers have a copy of the new "Thermal Guide" from AMD. Still, only a few manufacturers integrate thermal protection into the older motherboard designs, because this involves huge additional costs.
There are some examples of this to be found in the THG lab. The QDI Kudoz 7X with the VIA KT400 chipset (reviewed here), which arrived recently, implements overheating protection. In this technique, the data for temperature control (thermal diode) is read by the BIOS. The problem with this is that booting a PC without a CPU cooler takes too much time to ensure effective protection, with the result that the Athlon XP/MP CPU dies a thermal death.
Asus currently offers an interesting solution: here, the CPU temperature is monitored entirely with external circuitry on the motherboard. This results in more immediate reaction to temperature changes, nearly free of delay. Booting up without a CPU cooler and without having the CPU burn up is not a problem.
Comparison: T-Bred "B" Vs. T-Bred "A" Vs. Palomino
|Processor (Thoroughbred "A")||Clock frequency||Model Number|
|AMD Athlon XP 1500+||1333 MHz||1500|
|AMD Athlon XP 1600+||1400 MHz||1600|
|AMD Athlon XP 1700+||1466 MHz||1700|
|AMD Athlon XP 1800+||1533 MHz||1800|
|AMD Athlon XP 1900+||1600 MHz||1900|
|AMD Athlon XP 2000+||1666 MHz||2000|
|AMD Athlon XP 2100+||1733 MHz||2100|
|AMD Athlon XP 2200+||1800 MHz||2200|
|Processor (Thoroughbred "B")||Clock frequency||Model Number|
|AMD Athlon XP 2400+||2000 MHz||2400|
|AMD Athlon XP 2600+||2133 MHz||2600|
|AMD Athlon XP 2800+||2266 MHz||2800|
|AMD Athlon XP 3000+||2400 MHz||3000|
|AMD Athlon XP 3200+||2533 MHz||3200|
|AMD Athlon XP 3400+||2666 MHz||3400|
|AMD Athlon XP 3600+||2800 MHz||3600|
|Processor core||Number of layers||CPU classes|
|AMD Thunderbird||6||Athlon 650 MHz to 1400 MHz|
|AMD Palomino||7||Athlon XP 1500+ to XP 2100+|
|AMD Thoroughbred "A"||8||Athlon XP 1700+ to XP 2200+|
|AMD Thoroughbred "B"||9||Athlon XP 2400+ to XP 3400+|