The way the EVGA GTX 970 ACX heat sink was designed is based on the GTX 970 wattage plus an additional 40% cooling headroom on top of it. There are 3 heat pipes on the heatsink – 2 x 8mm major heat pipes to distribute the majority of the heat from the GPU to the heatsink, and a 3rd 6mm heatpipe is used as a supplement to the design to reduce another 2-3 degrees Celsius. Also we would like to mention that the cooler passed NVIDIA Greenlight specifications.
Due to the GPU small die size, we intended for the GPU to contact two major heat pipes with direct touch to make the best heat dissipation without any other material in between.
We all know the Maxwell GPU is an extremely power efficient GPU, our SC cooler was overbuilt for it and allowed us to provide cards with boost clocks at over 1300MHz. EVGA also has an “FTW” version for those users who want even higher clocks.
Regarding fan noise, we understand that some have expressed concerns over the fan noise on the EVGA GTX 970 cards, this is not a fan noise issue but it is more of an aggressive fan curve set by the default BIOS. The fan curve can be easily adjusted in EVGA PrecisionX or any other overclocking software. Regardless, we have heard the concerns and will provide a BIOS update to reduce the fan noise during idle.
Thanks,
EVGA