Originally Posted by sugalumps
Turns out it was the new gpu, think I got a real lemon. At 80mhz+ on the core it would just crash, could hardly maintain 2010mhz in game after throttling I think it must have been a faulty return. Put my 980ti back in and put a hefty overclock on it(still surprises me how low nvidia clocked the 980ti knowing how much it had in the tank) and my system is 100% stable rock solid again.
Reps to the people that said just go with a two slot cooler, I feel that's where the price to performance is this gen due to the power and heat limitations of all the cards it doesn't seem like a 3 slot is worth it unless you really need that 1-2% extra however it comes at the cost of sagging and £100+ extra. I will just go with a ventus, will try get the OC version at a decent price and call it a day.
Yes, the power consumption between a 2080 and a 980 TI is a little higher, but not that much (250W vs 283W in your case).
In fact the same PSU power is recommended for both cards.
So unless your PSU is high on the edge and the 2080 is just pushing it over the limit (unlikely), looks like a faulty card.
About the sagging on a big 3 slot card, if your motherboard PCI-E slot is metal reinforced and the card has a good back/inner plates, there's nothing to worry about.