these direct cu gpus are the coolest 7970s out there. i did only one day of testing - couldnt run psu at 110% for too long. but at stock clocks it did 60 to 70 C. overclocked one card peaked at 75 others about 70. oddly enough it ran cooler with door closed hence creating airflow i pressume.
Forced ventilation is (almost) always better than open air
But, what's your ambient temperature?
Intake temp is a priority to properly understand the airflow efficiency.
Thank you!
to be honest i didnt pay much attention to that. i had limited time to tinker with it since my current meter was going above 5A. i left this for now until i get 1500W PSU. i did my design based on many reviews saying 7970 dont go above 250W. though the current off the wall tells otherwise.
Try doing a lower voltage, might help you out in that