I have the 1080 Ti blacks. No header like this on the cards. Interesting.

cjsquirrel
I have the 1080 Ti blacks. No header like this on the cards. Interesting.

Wrong.

What do you mean?  The majority of video cards have a 4-pin fan header offering 4-pin PWM fan support.  Yours included.  Very few of the cheapest of video cards only have a 2-wire or 3-wire fan header with no PWM support.
 
 
 
On a video card though, the standard practice is to use a smaller-than-standard sized fan header in order to save space.  All you need is the correct adapter in order to adjust the size in order to plug into your standard 4-pin fan.
 
 
For one fan, keeping care not to exceed the video card's fan header amperage limit:
https://www.amazon.com/Gelid-CA-PWM-02-Adapter-Sleeved-Cooler/dp/B005ZKZEQA
 
Add this adapter after that previous adapter in order to split that one fan header into 4 fan headers and also no longer worry about the video card header's amperage limit:
https://www.amazon.com/Computer-Splitter-Connector-Sleeved-Adapter/dp/B00DYQRFY6

I am not having any luck finding the facts for these video cards, but typically fan headers are rated for 1 amp (12 watts).  For some reason, I am thinking that these EVGA video cards have headers rated for 2 amps (24 watts), but I don't know why I believe so and I definitely wouldn't recommend taking my word for it.
 
Either way, if using one high performance fan or more than one fan of any type, I would HIGHLY recommend that you use a splitter which provides fan power from a dedicated PSU molex connector instead of using the power from the video card.  It's just a really good idea, even if you think that the video card fan header would have worked fine without being overloaded.  It's not worth potentially ruining your video card for something so simple.  It doesn't need to be a "hub", it just needs to be a wired adapter cable splitter thingy (like the one I provided a link for) without having any additional circuitry or intelligence.  Fan hubs with intelligence are really a complete waste of money when connecting to a PWM header since all the required intelligence is already in the PWM header.   The only thing you should provide is power from an external source instead of using the header's power.

caligrown1985

ty_ger07
I am not having any luck finding the facts for these video cards, but typically fan headers are rated for 1 amp (12 watts).  For some reason, I am thinking that these EVGA video cards have headers rated for 2 amps (24 watts), but I don't know why I believe so and I definitely wouldn't recommend taking my word for it.
 

I find it odd there is so little information from the manufacturers regarding this connector. Should be on the specifications.

I remember an EVGA representative answering this question in the past, but can't remember the answer.  For some reason, I think that the answer was 2 amps in that instance, but I don't recommend that you take my word for it.  I would recommend that you plan for 1 amp or less.  It doesn't need to be on the specifications since it is not a feature EVGA intends for you to use differently.  It isn't on other video card manufacturer's specifications either, as far as I can find.