what case are you using ? having a proper case will play a major factor on heating issues concerning SLI I did in the past with my gtx 970s are side by side and went with a bigger case and solved my issue , proper air flow is the key for the gpus to perform without the issues of overheating , I had the exact same issue b4 and added some extra fans to arrange the airflow and never had that issue ever again if you don't listen than you can't blame anyone except yourself , been in this business too long and run a computer repair company and seen these issues day n and day out