I purchased an XPS 8900 I7-6700, 8Gb, 1Tb, NVidia 730 video on May 6. Out of the box the system is not stable. Connected up to my 4K monitor the video periodically blinks out (flashes a black screen), I get sporadic Window errors "The video driver has stopped responding" and it takes over 7 minutes to reboot (Shutdown and restart).
I did a reload of the system image of Windows 10. The problems persists.
I checked the bios version (it shipped with the latest bios), installed a fresh copy of Windows 10, made sure I had the latest Nvidia drivers. The problem persists.
I switched to the Integrated Intel graphics and the system is rock solid stable. I tried swapping a NVidia 980 card in... the system is back to being completely flaky again.
My conclusion is Dell has a BIOS conflict with NVidia cards. Did I miss something? I found many posts on the net about similar XPS / NVidia issues but they seem to be filtered from the Dell support website.
There are known issues with Nvidia cards. Dell Drivers and Downloads is the place to look for recent updates for the problem. Contact Support directly for help if that doesn't work.
Well, I hope you find the solution MikeInOr. I bought my XPS 8900 back in November. When I plugged it in I had the same issue right out of the box - the black flashing screen. To be honest, I didn't call right away to resolve the problem. I was able to use my sons laptop. December is a pretty busy time in my house and I knew I'd be on the phone forever dealing with support. I was right. My first call to tech support was more than 30 days after my purchase so my system could not be exchanged. I made numerous calls thereafter and finally got to the point where a technician was sent to my home. He replaced my hard drive and motherboard. He was at my home for 4 hours. Couldn't fix the issue. So I sent my computer to Dells "Repair Depot". It arrived yesterday with a letter stating Windows 10 was reinstalled and ... "Your system has been thoroughly tested and run through full system diagnostics by a certified technician based on the reported symptoms." Plugged it in today - still flashing. I was on the phone for over an hour with tech support today. They recommend I send it back to the Repair Depot which I'll do - AGAIN. So frustrating to spend money on a brand new computer that I can't even use! You seem more tech savvy than I but it appears you're still within 30 days of your purchase so you may have time to exchange yours for one that works. Good luck!
The GT730 is totally inadequate for 4K video.