Which is better for gaming?

The S90H. It lists a 165Hz refresh rate, VRR, FreeSync Premium Pro, G-SYNC, ALLM and a Game Bar. The S85H lists none of these, so treat it as a standard 60Hz-class OLED until Samsung confirms otherwise.

Is the 48-inch S85H worth stepping up to the 77-inch S90H?

Only if you have the room. The S90H adds a much larger picture, a faster panel, more ports and a fuller gaming and audio suite. If a 77-inch screen will not fit, the S85H keeps the OLED picture in a small size.

Both are OLED, so both can develop burn-in from static logos, news tickers and game HUDs over years of heavy use. Neither has a stated advantage in panel lifespan. Vary content and enable screen-shift and logo-dimming settings on either set.

Which is better for a bright living room?

The S90H lists a glare-free coating and Contrast Booster, which help with reflections. The S85H has no listed anti-glare feature. Neither OLED matches a bright LCD for peak brightness in a sunlit room, so control the light either way.

Do both run the same smart TV system?

The S90H lists One UI Tizen with Samsung TV Plus, Gaming Hub and built-in assistants. The S85H is a 2026 Samsung set and should run Tizen too, but its listing does not confirm the apps or voice assistants.

Which is better as a second TV or bedroom set?

The S85H. At 48 inches it fits a bedroom wall or the end of a bed and is easier to mount. The S90H is a main-room set that needs a large wall and a wide stand or mount.

Samsung S90HA OLED TV vs Samsung S85HA 48" OLED TV

The 77-inch S90H is the one to buy if you want a big, bright, gaming-ready OLED for a main room. Its 165Hz panel, four HDMI ports, Wi-Fi 6E and full gaming suite beat the 48-inch S85H on every count except size fit. The S85H is a smaller, simpler OLED for a bedroom, desk or tight wall, and it shares the same self-lit OLED picture quality but with fewer listed features. Reviewers and owners of Samsung OLEDs praise the deep blacks and wide viewing angles; the main complaints are burn-in risk with static content and reflections in bright rooms.

Choose the Samsung S90H if you have the wall space for a 77-inch screen and want 165Hz gaming, four HDMI inputs and Wi-Fi 6E.
Choose the Samsung S85H if you need a 48-inch OLED for a small room, a bedroom or a desk setup where a 77-inch set will not fit.

Prices

Samsung S85HA 48" OLED TV: $2,099.99 at Newegg (checked today)