NVIDIA has implemented a new power monitoring feature on GeForce GTX 580 graphics cards. Similar to our thermal protection mechanisms that protect the GPU and system from overheating, the new power monitoring feature helps protect the graphics card and system from issues caused by excessive power draw.
The feature works as follows:
Dedicated hardware circuitry on the GTX 580 graphics card performs realtime monitoring of current and voltage on each 12V rail (6pin, 8pin, and PCIExpress).
The graphics driver monitors the power levels and will dynamically adjust performance in certain stress applications such as Furmark 1.8 and OCCT if power levels exceed the card’s spec.
Power monitoring adjusts performance only if power specs are exceeded AND if the application is one of the stress apps we have defined in our driver to monitor such as Furmark 1.8 and OCCT.
Real world games will not throttle due to power monitoring.
When power monitoring adjusts performance, clocks inside the chip are reduced by 50%.
Note that future drivers may update the power monitoring implementation, including the list of applications affected.