Method and Apparatus for Processor Junction Temperature based fan speed control
Original Publication Date: 2009-May-19
Included in the Prior Art Database: 2009-May-19
Described is a method and apparatus for processor junction temperature-based fan speed control.
There are two problems solved by this invention:
1. Processor cooling is improved by tailoring the cooling for individual processors.
2. Processors can be adequately cooled while fan noise is kept to a minimum.
The idea here is to use many processor junction temperature sensors to determine the
cooling required for the processor rather than a heat sink thermistor. Also, this invention uses virtual product data (VPD) stored for each processor to tailor the cooling algorithm to that particular processor. The advantage this method has over previous methods is that it allows the fan speeds to be set more accurately. Rather than waiting for a heat sink to increase in temperature, many processor junction temperatures are read (hereafter referred to as Tj). Since the Tj responds faster to increased processor temperature, the fan speeds can be set more quickly and accurately in response to an increase in temperature. Also, since the individual processor VPD is used to provide a weighting factor for the individual Tj sensors, the algorithm will be individually tailored to a particular processor. This reduces the safety margins that normally need to be built in to the fan speed settings and allows the fans to run slower and quieter while still providing adequate cooling. The unique tailoring of the fan speeds to the individual processor is the core of this invention. This invention works as follows:
1. When the processor is built, multiple Tj sensors are distributed throughout the chip a...