AMD’s reference RX 7900 XTX features a unique ambient thermal sensor allowing the GPU to measure air-inlet temperatures that directly get into the cooler. It is still not known why AMD added this sensor to its cards, but it is quite useful. 

There are various benefits of having an ambient thermal sensor inside your GPU cooler. One of the most important advantages is to monitor ambient temperatures while the fans are off, in order to keep PCB components on the card from overheating. 

This was a problem on EVGA’s GTX 10 series graphics cards prior to the introduction of ICX coolers. The 0db mode of the cards caused power delivery components to overheat and die prematurely. As an outcome, EVGA recalled those cards and replaced them with ICX coolers featuring extra thermal sensors. 

This was a one-time ordeal, and every card on the market today has a zero RPM fan mode, along with coolers that have been designed to take advantage of the said feature. 

AMD added this sensor as an added security measure, just in case PCB components get too hot while the GPU core is still cool enough to keep the fans off. Once temps get too warm, the card can start a secondary fan curve to keep the PCB components cool at the time of operating the fans at a very low RPM. 

AMD will also give end-users access to this sensor inside the Adrenalin control panel as it could be really helpful in several cases. For example, the ambient sensor can measure the actual ambient temperature inside the whole system to monitor as well as troubleshoot high temperatures on other components. 

AMD ignored to share why it has added this sensor to its reference cards. All we have to do is anticipate. But if we receive an official comment from AMD, we will definitely update you here.