What we tested
Six weeks in a living room with mixed lighting conditions — bright mornings, blacked-out evenings, and everything in between. We watched sport, films, TV series, and played games on both PS5 and Xbox Series X. Our tester has owned a Samsung QLED for four years and upgraded specifically for this review.
The S90C sits in an interesting spot. It uses QD-OLED technology — quantum dot on top of OLED — which means it competes with LG OLED panels on picture quality while Samsung claims better brightness. Most of those claims hold up.
Picture quality
Exceptional. The blacks are as deep as any OLED we've tested, colours are more saturated than standard OLED without looking oversaturated, and peak brightness in HDR content is noticeably higher than LG's equivalent panels at this price.
Sport looks stunning. Fast motion handling is the best we've seen at this price point — no ghosting, no blur, just clean movement. If you watch a lot of Premier League or F1, this matters more than almost any other spec.
Films in a dark room are where this TV earns its score. The contrast is the kind that makes you forget you're watching a screen.
Gaming
Two HDMI 2.1 ports, 4K at 144Hz, VRR support, and a Game Hub that actually works. Input lag in game mode measures at around 1.5ms — effectively zero in practice.
The only frustration is that Samsung locks some of the better gaming features behind specific HDMI ports. Read the manual before plugging anything in or you'll wonder why you're not getting 4K 120Hz.
The software
Tizen is Samsung's smart TV operating system and it is the worst part of owning this television. It's slow, the home screen is cluttered with promoted content you didn't ask for, and finding the input you actually want takes more button presses than it should.
You will get used to it. You will not like it. If software matters to you, a separate Apple TV or Nvidia Shield plugged in solves the problem entirely.
Sound
Adequate. The built-in speakers are fine for daytime TV and get loud enough for a medium sized room. For films and gaming you will want a soundbar. Factor that into the budget.
Should you buy it
At around £1,299 for the 65 inch it's a serious purchase. The picture quality justifies the price if you watch a lot of films or sport in a properly set up room.
If you're upgrading from a 4K LCD TV from three or four years ago, the difference will be immediately obvious and you won't regret it.
If you mostly watch daytime TV in a bright room, spend less. The S90C is at its best in controlled lighting. In a very bright room the advantage over a good LCD narrows considerably.