I have had my build now for nearly a month. I went with the Gigabyte Z170X Gaming 3 as my motherboard. I had a GTX 1060 6GB in it for about a week and all was well. I decided for the small difference in price that I would go with the GTX 1070 and so I did. Ever since then, I have been getting random no posts at startup. Its rarer than not but still. Ever since I swapped it out. Happened that day. My case speaker makes no beeps or anything the computer just sits there spinning the fans. No power to usb either. I read one post about gigabyte motherboards having issues with card with high amounts of VRAM and I believe that the GTX 1070's 8GB probably falls into the high category. Any one else experience this? I have 3 days to return it trying to make up my mind.

In my opinion the 1070 is not worth the increased price over the 1060 6GB for the negligible additional performance it offers.

 

However, if you do decide to keep your 1070, it should certainly be compatible as far as I know. You may have a faulty motherboard? You may have broken something when replacing your GPU, too.

Edited October 27, 20169 yr by Albo1125

Try disassembling everything, dusting it all off, and putting it back together.  Run it a few times over the course of a day and see if it persists.

I wondered about breaking something. The 1060 was a bear to remove. Turns out it was caught on one of the screws for one of those pci delete plates on the case so pretty sure all the force that I was putting was going on the screw not the slot. It's so random and rare that it's hard to replicate. I have pulled the card out before. I reseated the ram and the problem was gone for 8 days till it came back and I had to power cycle it 3 times for it to finally post. 

Just made a video of it happening.