Thermal Algorithm

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

Temperature Targets

The system fan is 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 Falcon.

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