I've seen on Arctic's site that they rate their passive by design S3 for 135W, and from the one test I saw it does a very good job of it too. I've tried to Google up some experiences about any variant of the Xtreme running with no fans, but it seems nobody has them and I feel like I shouldn't just assume that the larger fin array will simply scale up to cover my 180W card passively. Has anyone here seen a test or tried to do this per chance, or is anyone willing to run a quick test on any card that takes ~180W or more? My gut feeling tells me that it should be okay but I'd like to base a purchase decision on something a bit more substantial. While I normally just love any opportunity to go fanless for the sake of it, I do actually have a practical reason for wanting this. My case will accommodate the length of the cooler, but it is too thick to fit with the fan assembly on. I'm also keeping in mind the smaller components on the card that might be relying on incidental airflow, and I'm hoping that the two Noctua A14s I bought as front intakes will be able to take care of that. Any input is hugely appreciated.