We first measure GPU temperature while the card is sat idling at the Windows 10 desktop for 5 minutes. Gaming GPU temperature is recorded by running Unigine Heaven DX11 benchmark for 5 minutes. As a maximum stress test, Furmark is run for 5 minutes and the cards' GPU temperature levels are recorded.
Ambient room temperature was held between 17 and 18°C.
The triple-fan DirectCU III cooler does an excellent job at taming the GTX 1080 GPU. Its cooling performance is better than the Gigabyte G1 Gaming card's and only the liquid-cooled AMD Fury X is able to offer lower temperatures in our testing comparisons.
64°C under load is absolutely no cause for longevity concerns and it's nowhere near the ~83°C point of temperature-induced GPU clock speed throttling. 29°C when idling, without the fans spinning, is also worthy of praise.
ASUS' backplate does a good job at spreading thermal energy across a large surface area and preventing a distinct high-temperature hot-spot. I would have no concerns about plastic fan cables laying on top of the card as these temperature levels are unlikely to cause any form of melting.
The rear-mounted capacitors directly above the board's MOSFETs showed up as the hottest part of the card. A cut-out in the backplate is probably partially responsible, but even at ~53°C after a period of heavy load, this is no cause for concern.
Good job with all-round cooling for the ROG STRIX GTX 1080 A8G, ASUS.
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