rMBP 2015 15-inch using lots of vram on external display

[Penderworth]

Hey folks!

For some reason, when I'm using my 23-inch Cinema Display with my 2015 Retina MacBook Pro 15-inch, the fan spins up, iStat reports overall temperature of 152°, and the poor Radeon's memory is nearly maxed out. I wouldn't mind so much if it didn't spin the fan up and heat my fingertips. I've searched around and not heard of anyone else with this issue, so maybe I'm alone. If I am, where should I start with diagnosing things? Or should I just go straight to the Bar?

Thanks!

 

[Penderworth]

Bumping this one. Any ideas from you smart people out there? Should I just take it into Apple and get some diagnostics run on it?

 

[BittenApple]

Reset the PRAM? SMC reset?

 

[Penderworth]

Reset the PRAM? SMC reset?

I've tried both multiple times. No luck.