"Mostly fine" is something to worry about? regarding the 90s, you mean the gpu temp or junction?
No, temp junction is normal. Your temps are okay. The GPU temp that you see (78*c) is the traditional sensor. That should be under 90 - the junction is the hotspot. It's always in the 90-100 range but only AMD cards display it since Nvidia hide that sensor to make the card appear cooler to less knowledgeable users.