I've been having problems getting my 980 Ti to work as the primary graphics output on my computer.
Before I go into details, I'll post my build:
ASRock Z97M OC Formula
Intel Core i7-4790k
DDR3-1866 (2x 8GB)
280mm AiO
EVGA GTX 980 Ti Reference card (non-SC/ACX 2.0)
Wireless adapter card
Samsung SM951 256GB M.2-2280 (AHCI, not the NVMe version)
500GB SSD (boot drive)
4TB HDD
EVGA SuperNOVA G2 1300W PSU
Windows 7 Professional 64bit
* - Everything is left at stock speed/settings apart from the RAM, which I had to force into a built-in XMP profile to run at its normal 1866MHz speed
 
When I first installed my 980 Ti, the entire build would not POST (the screen kept saying "Please insert the 4-pin power cable into your motherboard"), so I called EVGA customer support. After flashing the mobo's BIOS and moving the 980 Ti to the two PCIE slots, they said that it was likely an issue with my PSU and RMA'd a replacement.
When the replacement PSU arrived, I called customer service again because I was still getting the same message, but this time the customer service rep (I think his name was Lee) told me that there was a four-pin MOLEX connector at the bottom of my mobo (the previous rep told me that my board didn't have one, hence the RMA). I plugged that in and the error message went away, but it would still refuse to boot into the OS. The rep told me to contact ASRock because this didn't appear to be a hardware issue with either the card or the motherboard, but a BIOS or firmware issue. So, I contacted ASRock and they told me that my mobo was functionally fine would fully support the 980 Ti with their latest BIOS, which I reinstalled after resetting the board's CMOS. No further actions or recommendations were made on their end.
 
Now, after fiddling with the BIOS to get everything working properly, I noticed that the M.2 drive was interfering with the boot order on my UEFI settings. I moved my OS from the M.2 to the other SSD, removed the M.2 from the socket, and tweaked the BIOS to disable M.2 mode to find that the entire build worked - the video output was working from the 980 Ti and my OS would boot normally. I had to update the 980 Ti's BIOS to get my computer to fully recognize it, but it was a start. I tried benchmarking the card while I had it on, but none of the software I used would start with the 980 Ti, stating that DirectX 9, 10, and 11 mode were disabled on the card. None of the games I had on my computer would start, giving me a similar "DX9/DX11 is not supported" or "DX9/DX11 extension is missing" message as with the benchmarking software. I reinstalled and updated DirectX, but nothing changed.
Frustrated, I decided to reinstall the M.2 and re-enable M.2 mode on my BIOS. Those two changes caused my entire system to fail to boot. I uninstalled the 980 Ti and triple-checked the BIOS settings to make sure that CSM was enabled and that both storage and video modes were set to Legacy, not UEFI. My OS booted fine that time.
Plugging the card back in and enabling PCIE as the primary video adapter caused the OS not to boot again.
 
Right now I have the 980 Ti plugged in, but I'm still using the integrated graphics on my CPU because the computer will not boot into the OS otherwise. The computer recognizes that there is a 980 Ti plugged in, but it simply will not use the card for any games or software I have.
 
I've been googling this issue for over two weeks now and I haven't found any solution that would work on my build. Customer service haven't been able to figure out what is wrong with my card and/or motherboard. This is the last place I can turn to for help before I return this card for a refund.
Is there anyone here at the EVGA forum that can help me?