Let's hope it works out of the box, because getting Dell to update the MB bios to support the 970/980 was like pulling teeth. No way are they doing another bios update for us for Pascal.
I'm hoping it works out of the box since a representative said this for the 8900, "The GTX 1070/1080 will not be validated by Dell on the XPS 8900 due to its 460w power supply. This also means that we will not be writing a bios update to address those video cards. If validated by Dell, it will only happen on the Alienware Area 51-R2 which has the 850w and 1500w power supplies."
I am helping my friend build a computer with a 1070 GTX. Assuming I am able to land one for his build on release before it's sold out everywhere (a real possibility because demand for it is insane). I will make sure to stick it in my 8700 for a test run and report back to you guys.
Somebody needs to test this out! I was the guinea pig for everyone with the 980 Ti, which ended up working.
I'm also interested to see if a AMD 480 works as well! Hope someone will test that out.
Thanks for writing to us.
GTX 1070/1080 are not tested by Dell, but below are the ones which are sure to work with XPS 8700.
These are the models tested by Dell if you are interested in one of them.