The reference cards are going to get up to their temp limit and then adjust their boost clock accordingly. As long as its above its 1075 rated boost clock there is nothing wrong with the card. If you want higher boost clocks use afterburner and up the temp target a few degrees and up the power limit to 110% then make the temp target the priority. should help you out.
I have two reference 980ti's and both are overclocked +250 core and maintain boost @ 1400 mhz under load with 86C temp target. Top card fan gets up to around 60%, bottom card fan gets up to 45%
68%top 85% bottom asic scores.