I'm pondering the possibility of a second strix to do me to the end of next year but not really sure how it would work in terms of acoustics and thermals. I seen the oc3d review where he says a single card is whisper quiet (it isn't, its not loud but it can be heard but its not intrusive) and sli is "very quiet" according to him.
Playing war thunder my strix maxed at 78c at 1425 mhz default core voltage 110% power target. And seeing as a second internal blower card seems to add around 10c to the top card I'm not sure how 2 of these would fare. I can have a decent amount of space between them (about 3 slots) but at the same time I'm not convinced the fan would stay under 50% which is where it gets more audible.
Was considering redoing my thermal paste on the card as the way this heat-sink is layed out its a pretty weird application. From the pics I've seen the heat-pipes have gaps between them thats filled with TIM, so it seems to be splodged on more than if the core were meeting a solid flat surface. So seems to be a bit more than what you would expect on the core.
Random google image of it ^
Hmm, have to think about it. A single card does decently well in 4k, but a second would tide me over for another 12-18 months hopefully. Just not sure what to do yet. =/