Which is better for gaming, the S90C or the C4?

The LG C4. It has four HDMI 2.1 ports, up to 144Hz refresh, 0.1ms response time, and G-Sync plus FreeSync Premium certification. The S90C is fast but has fewer 2.1 inputs and no G-Sync certification.

Is the C4 brighter than the S90C?

Yes. The C4 uses an OLED evo panel with Brightness Booster, which lifts peak brightness above the S90C's standard OLED panel. The gap shows most in bright rooms and HDR highlights.

Does the S90C support Dolby Vision?

No. Samsung TVs use HDR10+ instead. The LG C4 supports Dolby Vision and Dolby Atmos, which matters for Dolby Vision movies and shows on Netflix and other services.

Which has better smart TV software?

They are close. Tizen on the S90C is fast and has most major apps. LG's webOS on the C4 is equally complete and comes with a five-year update commitment through the Re:New program.

Is the C4 worth stepping up to over the S90C?

For gamers and movie fans, yes. The extra HDMI 2.1 ports, 144Hz, Dolby Vision and brighter panel are real upgrades. Casual viewers in a dim room will find the S90C close enough.

Both use OLED panels with similar lifespans under normal use. The C4's five years of webOS updates keep its apps current longer, which extends useful life more than hardware differences do.

Samsung S90C 65" OLED TV vs LG OLED evo C4 65-Inch TV

The LG C4 is the better TV for most people. Its OLED evo panel with Brightness Booster is brighter than the S90C's standard OLED, and its four HDMI 2.1 ports, 144Hz refresh, G-Sync and FreeSync make it the stronger gaming set. The Samsung S90C is a solid 65-inch OLED with Tizen and good color, but it is an older generation with fewer gaming features and lower peak brightness. Owners and reviewers consistently rate the C4 higher for picture processing and gaming.

Choose the Samsung S90C if you want a 65-inch OLED with Samsung's Tizen app platform and a simple, bright living-room picture.
Choose the LG C4 if you game on a console or PC, watch movies in Dolby Vision, or want the brighter OLED evo panel and four HDMI 2.1 ports.

Prices

LG OLED evo C4 65-Inch TV: $79.52 at thepatioandperch (checked today)