Thermal Algorithm

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The Xbox 360 uses a dynamic Thermal Algorithm in order to control the temperatures of the CPU, GPU, and eDRAM dies.

Temperature Targets

The Fans are controlled by the SMC dynamically to keep the thermal sensor readings at or below the targets. The previous value of each sensor is used to determine the rate of increase, in order to prevent overshooting the targets. These temperatures are designed to balance being a large margin below the Trip Temperatures, while keeping the acoustics to a minimum.

Original Xbox 360

Board CPU GPU eDRAM
Xenon 80C 83C 85C
Zephyr_A 80C 83C 85C
Zephyr_B/C 80C 75C 78C
Falcon 80C 75C 78C
Elpis 80C 75C 78C
Jasper 80C 71C 73C
Tonasket 80C 75C 77C

Note: Refurbished Xenon and Zephyr_A motherboards are modified with the temperature targets from Elpis/Falcon respectively.

Xbox 360 S and E

Applies to Trinity, Corona, Waitsburg, Stingray, and Winchester.

CGPU Hot Spot CGPU Average eDRAM
82C 78C 76C

Trip Temperatures

At these temperatures, the SMC enters the EC_THERMAL error state in order to cool down. It should be noted that these temperatures are a margin of error below the actual chip Tjmax, which is significantly below the temperature where the chip would stop operating correctly. As a result, these trip points will always be quite a bit before a catastrophic failure due to thermals would occur.

Original Xbox 360

Board CPU GPU eDRAM
Xenon 100C 110C 117C
Zephyr_A 100C 110C 117C
Zephyr_B/C 100C 100C 102C
Falcon 100C 100C 102C
Elpis 100C 100C 102C
Jasper 95C 90C 92C
Tonasket 95C 90C 92C

Note: Refurbished Xenon and Zephyr_A motherboards are modified with the trip temperatures from Elpis/Falcon respectively.

Xbox 360 S and E

Applies to Trinity, Corona, Waitsburg, and Stingray.

CGPU Hot Spot CGPU Average eDRAM
89C 82C 82C

Applies to Winchester.

CGPU Hot Spot CGPU Average eDRAM Area
91C 82C 91C