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 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.
Original Xbox 360
| Board | CPU | GPU | eDRAM |
|---|---|---|---|
| Xenon | 80C | 83C | 85C |
| Xenon (Refurb) | 80C | 75C | 78C |
| 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 |
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 |
| Xenon (Refurb) | 100C | 100C | 102C |
| 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 |
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 |