Hi guys,
I own a EVGA GeForce GTX 1080 Ti SC2 GAMING, 11G-P4-6593-KR and mounted the EVGA Hydro Copper Waterblock for GTX 1080 Ti 400-HC-5599-B1 a while ago.
I am planning to syncronize it´s RGB lights with the others in my RIG controlled by a ASRock Z370 EXTREME4 Motherboard.
Unfortunately there is no software solution to sync these components so I want to try to connect the RGBs of the Hydro Copper Waterblock directly to my MB. 
My plan is to use a cable from the Motherboards RGB output and connect it with the connector on the Hydro Copper but I need to make the cable on my own because the connectors a different.
I don´t want to cut the wires on the Waterblock so I need the counterpart of that one but I couldn´t find out which one I need. Is anyone able to give me the name or a partnumber of that connector? I attached pictures of the one I am looking for.
If anyone knows an other option to syncronize the devices feel free to tell me.

Cool GTX
Maybe this will work ?
 


Product EAN:
3830046995445

Even though the adapters connector isn´t exactly the same, the male one might fit if the distance between it´s pins is the same (or it will fit with some adjustment).
I will try that if nobody else can give me the exact counterpart I am looking for.

As far as I know, all EVGA RGB LED component pinouts are wired +12V, then RGB (see Post #7 here)..The RBG LED pinout of the ASRock Z370 EXTREME4 is +12V, then GRB (see page 25 of your mobo manual).
 
You could buy that short adapter cable that Cool GTX linked you to and remove/rearrange the terminals on that, or cannibalize it by cutting/stripping the wires and put them back together again with the proper pinout from the mobo..However you wanna do it..Just don't lose track of which wires are which, temporarily label them.
 
Hope that helps somewhat.

0bonestorm0
OK so now I built my own cable system to connect all of my RGB devices to the header of the ASRock and before I connected the EVGA RGBs it worked fine. The problem was that the RGB connector on the EVGA Waterblock has 6 PINs and not the common 4 PINs for RGBs. The EVGA support wasn´t able to give me the connector assignment so I had to figure that out by myself. Unfortunately 2 of the 6 PINs on the connector caused an short circuit breaking the LEDs in the Waterblock and also damaged the MBs RGB controller so now I always have full power on blue on the Headers Output. Well, not the first stuff I broke and probably not the last, **** happens.
Nevertheless thanks for your help guys.

I'm not trying to make you feel worse, but I am glad you posted this. There was a rather umm...vigorous discussion awhile back where some were trying to argue it was completely harmless experimenting with wiring LED's because of the 'low voltage'. The saving grace in your example is  in using a motherboard header as the low current supplied by the header, limited the damage. Those wiring directly into the PSU for either +5 or +12v get no such protection.

I had very poor equipment and tools to do testing (no multimeter), but yeah using a battery might have been a good idea. Maybe I will try to find the broken component in the waterblocks electronics but that´s a project for my next semester break. I 
probably won´t be able to fix the MBs Header and I am not sure  if I even want to try it. My last attempt in SMD soldering didn´t work as planned ;-)