Both sound amazing on paper. The 780 is a 780, not a Ti... so that's slightly disappointing. That being said, its clocked with base over 1GHz which is pretty good, but I do wonder if the "hybrid" cooler will allow it to be cooled via air sufficiently. I presume that one can run both the liquid and the air cooling on the card for even better heat dissipation so if I had the money and the card wasn't ridiculously overpriced, I may consider it. As far as the MARS760 goes... I am interested in it because my current mobo has only one PCIe 3.0 slot. However, seeing the price of $650 on newegg was like a thorn in my eye (especially when single 2GB cards go for less than $250). For that much money, the card should have been 2x4GB and not 2x2GB. Regardless of my opinions, if anyone wants to preorder the MARS760 here's the link - http://www.newegg.com/Product/Product.aspx?Item=N82E16814121839

Honestly, I think they're both a bit rubbish really. As has been pointed out the Mars is only 2GB VRAM and costs more than two 4GB cards in SLI and will have worse performance...OK for the restricted PCIe lanes case but for anyone else...does not make sense...

The poseidon...good waterblock on a 780 is going to be better.....dedicated air cooling on a 780 is going to be better. Air and water cooling run together on this card is going to be better than just air but so what....
Would be interested in materials in water block...for corrosion....any one know any aluminium?

Both gimmick cards for me....pretty disappointed frankly...ROG school report card reads "needs to apply themselves more...could do better"

Arne, on matters of the air cooling it says on its webpage that it air cools better by 20% than the standard version. Although I agree with you on the liquid cooling.