Darn just tested new gtx 1080 sc and seems i have same fan issue. I hope there is some relatively easy fix on this.
 

First, I hope this gets cleared up for everyone, especially if it's a bug. 
 
I bought and received a 1080 SC in July and don't have this issue. 
To test, I removed Precision XOC and loaded up GPU-Z. I set the sensors to monitor just a few items. I then ran the Firestrike benchmark and logged the data to a file. I generated the attached chart which shows my fan curve being pretty smooth. Fan speed throttles up as gpu load and temp rises and throttles down as load and temp reduces.  The fan curve is, therefore, the one built into the drivers/card and not customized in any way. When I run Precision XOC, though, I run at a more aggressive fan curve. 

Also it's worth noting I'm using Nvidia driver version 375.63 and GPU bios version 86.04.17.00.80.
 
 

anyone get a replacement card yet that does not have the issue? 

Is there any update from EVGA on this issue?

rojaho1
Is there any update from EVGA on this issue?

 
Couple days back, EVGA finally reached back saying that they have now identified the fans issue and can resume the RMA request. However, I have returned the SC to the retailer as my return window was closing, so can't provide further insight.

Got my third RMA today, they told me they did extra testing and assured me it was fixed. The card runs quiet as a mouse and the fans are stable, i am glad its over