Power Monitoring hardware
Power Monitoring hardware
ATI implemented this on the R5000 and newer series, NVIDIA now follows. Two small ICs are embedded on the PCB that monitor temperatures and power load on certain phases of the PCB. A new power monitoring feature as such has been implemented. Dedicated hardware on the PCB monitors current and voltage on each 12v pin leading to the graphics cards.
The driver will monitor the power levels and can dynamically adjust performance, this should kick in especially with stress software like Furmark & OCCT .
We tested the feature deeply and not once did we notice a clock down or anything with Furmark. Also, overclocking wise we were wondering if the feature would kick in and prevent overclocking. As you will notice later on in our review, overclocking was not hindered by this either.
Personally we do not like this feature whatsoever as in certain conditions it could kick in and clock down the graphics card. For extreme overclockers (LN2) we expect a lot of issues though. The NVIDIA board partners can decide for themselves whether or not to implement this on their own custom boards though all reference boards will have this protection.
NVIDIA's latest email on the topic:
Earlier we briefed you about a new feature we called Advanced Power Management. The below information is intended to clarify. First, here are the correct facts about our new technology:
We have implemented new power monitoring and power capping features on GTX 500 boards. Similar to our thermal protection mechanisms that protect the GPU and system from excessive heat generation, the new power monitoring and capping features help protect the graphics card and system from issues caused by excessive power draw.
- Dedicated hardware circuitry on the GTX 500 series graphics card performs real-time monitoring of current and voltage on each 12V rail (6-pin, 8-pin, and PCI-Express).
- The graphics driver monitors the power levels and will dynamically adjust performance in certain stress applications such as Furmark and OCCT if power levels exceed the cards 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 and OCCT.
- So far we have not seen any real world games that are affected by power monitoring or need power throttling to stay within spec.
- We restrict power monitoring only to stress apps, because we dont want to limit customers who want to overclock games, and we believe the stress apps are the key apps where the graphics card can benefit from additional protection mechanisms.
- We will enable power monitoring for older Furmark versions in future drivers. The 262.99 driver only identifies Furmark version 1.8. If other thermal stress apps are discovered, they will be added to the protection mechanism from time to time with driver updates.
- We do not provide any end user ability to turn off power capping today.
- The power limits for GTX 580 are set close to PCI Express specs for each 12V rail.
- In this initial implementation, when power capping becomes active, clocks inside the chip are reduced by 50%. Many 3rd party tools have not yet been updated to show this fact, but we suspect updates will be coming to make the internal clock reductions more visible.
The text above more accurately describes our actual operations.
