980 ti issues?

- how not to run a 225+ watt card -

This 290x user had shutdown/restart issues because only one vid-cable's plugged in: the primary & 2ndary jumper only. The 875w power supply has two 12v rails; each rail is rated at 216watts (18Amps); above we're looking at a 250watt card starving off one 12volt rail; the power supply will trip after it sees 216w over that cable, & restart in an attempt to remove the load etc. After unplugging the jumper part of that cable & inserting the primary ('the other 12v rail') from the unused cable the issue stopped; the card was well-fed & had access to over 430watts of 12v juice.

Your case harness has two actual vid-cables, use 'em both, see how it turns out.

when running a solo-card, & you need an 8pin? --> borrow the 2pin from the 2ndary jumper <--

- there's a better way than this -

that high-power GeForce needs a pair of 8pins; the answer isn't to lay the primary 6pins to the side un-used so they dangle in mid-air, the answer's to use / insert the primary 6pin & 'borrow' the 2pin from the jumper; lay those resistive jumpers to the side, snatch the 2pins, use them as I've done below:

it's tough to see the jumper's not being used in my cropped pic, but I've certainly inserted my white primary 6pin - laid the jumper part of the cable to the side (exit stage left) & 'borrowed' the 2pin off of it. The primary 6pin is the path of least resistance, the 2ndary jumper 6pin is more resistive so I don't use it, just the 2pin, that I use. Try it. Always use your primary 6pins when you have the chance.