What's a safe GPU temperature while gaming?

Check which temperature you're actually looking at. Newer cards report a hotspot (or junction) temp alongside the normal GPU temp, and the hotspot one runs a good 10-20 degrees higher. People see 95 on that reading and panic when it's completely normal.

83 is fine. Most cards are built to run in the 80s under load and only start throttling somewhere around the high 80s to 90. No crashes and steady clocks means it's doing its job. If the fan noise is the annoying part, a custom fan curve or a small undervolt in MSI Afterburner usually drops a few degrees and a lot of noise with almost no performance loss. Clean the dust out of the cooler too if the card is a couple of years old.