I started this thread here before I purchased the Poseidon: https://forums.evga.com/Should-I-get-the-EVGA-Hydro-copper-Asus-Poseidon-or-ek-water-block-m2697357.aspx
 
I've had the Poseidon for a couple weeks now. One of the reason I went with it was it has two external fan headers. I was planning on connecting my 5 radiator fans to those heasders and using GPU Tweak to control them. The reason why I wanted that is my mobo 4 pin headers are not actually PWM except for the CPU and that I am using with a D5 pump. I have been using Speedfan but I've wanted something better to control the fans. I was hoping the Poseidon headers were the answer. Well after hours of testing the short version is the fan headers won't recognize any fans after calibrating them. I tried "known to be good" PWM fans, 3 pin fans, etc. None of them would be detected after calibrating. It always said "detect failed". Which means I couldn't control the fans the way I was hoping. I even tried a Swiftech 8 fan externally powered fan splitter and that also didn't work. I tried every software, drivers, etc, that Asus told me to and nothing worked. By the end they offered me an RMA. I told them there is no way I am RMAing a $870 video card and receiving a refurbished one simple because the external fan headers aren't working. I decided to contact Newegg directly and after a long chat session they agreed to offer me a full refund. The issue is I bought it through Ebay using $140 of Ebay bucks so God only knows what will happen if I return it. I might have to contact Ebay to get the $140 Ebay bucks back and there is no guarantee that will end well.
 
I ended up buying a NZXT Grid V2 to control the fans. That is working great so I no longer need the fan headers on the Poseidon.  
 
So here I am now. I added the Poseidon to my water loop Tuesday. It is performing very well. At stock settings it is boosting to 2012-2025mhz and doesn't bounce around at all. Temps are in the low 40s. If I raise the power to 120% without adding voltage it will sometimes hit 2050mhz. Overclocking will hit 2100mhz but it isn't stable. It appears 2088mhz is fairly stable and 2075mhz is rock stable.
 
It appears I got a decent overclocking 1080ti. Should I return the Poseidon and try a different 1080ti like the Hydro Copper or another card with an EK block? Should I just stick with it since it does appear to be a decent clocking card? I do like the aesthetics of it and the fact I can air cool it if needed is a nice feature to have when working on the loop. 
 
Let me know what you guys think.

Will do. Thanks for the reply!

Should I get the EVGA Hydro copper, Asus Poseidon, or ek water block? Wait this is yours
ASUS ROG-Poseidon GTX1080Ti
 

I emailed Asus as well as EK. I will post once I hear back from them. Hopefully the Poseidon waterblock is not bare aluminum but it might be. If that is the case then it appears I should return it or risk damaging my loop. 
 
Edit: Is it ok if the Poseidon block is made of aluminum as long as I use coolant that has corrosion inhibitors in it? I have been using EK dye with distilled water that does have corrosion inhibitors. 

I hope it isn't aluminum. I can't find a solid answer anywhere. I did see one post that said it was copper but who knows if that is accurate. The base plate that contacts the core is copper but that doesn't mean the water channels are.

beekermartin
I am going to contact EK and see what they have to say about the Poseidon water block. If they say it could cause an issue with it being made of aluminum then I will be returning it.

The Poseidon uses the same pcb as the Strix,so you can use any Strix compatible block.

AdamInk
Just keep in mind if you dissamble an Asus card you void your warranty!

Not true. I had two different reps assure me that it won't void it if everything is put back together.

GTXJackBauer

Skizzy34

AdamInk
Just keep in mind if you dissamble an Asus card you void your warranty!

Not true. I had two different reps assure me that it won't void it if everything is put back together.

I would take anything Asus says with a grain of salt.

Sadly thats true, their costumer support its not on the top of the mountain. I had problems with my previous asus cards, no way to goin back.

Moving to General Hardware as this is an Asus product
 
EVGA GeForce 10 Series --> is for EVGA GPU

No problem - just house cleaning.  The note was meant to be informative
 
Good luck figuring what to do with your GPU

I also doubt it but looking in the holes with a flashlight it does look like bare aluminum. Not nickel plated copper which would be shiny.

I called Asus again today and I still can't get an answer.

I wouldn't say I have a golden card but it does seem to be stable at 2075 mhz. That isn't bad for a 1080ti but not incredible either.

I have thought about keeping it and getting an EK block but that would put me over $1000 total. I think I am better off returning it and getting a cheaper card with an EK block. Most 1080ti's will overclock to 2050 mhz from what I have seen. If I get a card that doesn't overclock as well as the Poseidon I doubt the difference will be much.

I am going to decide tonight. If I do end up returning it and I find out later from Asus that the run channel is not aluminum I could always buy it again. The issue is my return window is almost up so I need to decide tonight.

dakon
The water cooling parts are copper.  There is aluminum in the air cooling system.  Check on some reviews.

I have spent hours watching and reading every review I could find. They all show that the part that touches the core is copper. I haven't found one review that discusses what the water channels are made out of. Even Asus can't give me an anwer. lol
 
I would be shocked if Asus actually used aluminum. I would like to think they wouldn't have done that. Still I don't want to take a chance destroying my loop.  
 
I will keep contacting Asus until I get an answer but it sounds like it will take a few more days since their system is still down as of today. 

thanks for the update

I ordered a Gigabyte Aorus Extreme 1080ti today. Massdrop had it for $679 with free shipping. It sold out fast. I won't receive it until the middle of September but I can deal with that. I will order an EK block for. It will end up costing me less than the Poseidon if I don't get the optional EK back plate. According to the EK website the factory back plate is not compatible. I don't understand why. I imagine I can make it work. Hopefully I get lucky in the silicon lottery and I get similar clocks with the Aorus that I had gotten with the Poseidon. 
 
Still no answer from Asus...

Wow not very helpful

Thanks for sharing