LG OLED G6 (G64LW, G66LS) vs Samsung S90H (WOLED)

The LG G6 is currently one of the brightest OLEDs on the market. Its peak brightness reaches nearly 2500 nits, and what’s best – this has a direct impact on real film scenes. The television flawlessly extracts details in the bright areas of the image. And this is regardless of whether we are talking about very small points like stars in the sky or slightly larger elements on the screen. Naturally, with full-screen, uniformly white scenes, the brightness of the G6 decreases due to the panel protection system (ABL). However, in real, varied cinematic shots, this value still hovers around 2000 nits, which can be considered an outstanding result. The coverage of the colour palette also deserves praise. The new second-generation Tandem OLED panel only brought a cosmetic change but still an improvement. The coverage of the DCI-P3 palette reaches nearly 99.5%, whereas for the ultra-wide BT.2020, it is around 84%. These are very good results, although it’s worth remembering one thing: at extremely high brightness levels, the colour volume will be lower than in Samsung Display’s QD-OLED panels due to the use of a white sub-pixel (WOLED). However, in everyday content and most films, catching this difference will be very difficult.

Samsung S90H in the WOLED variant is still an exceptionally bright TV for its price bracket, although compared with the QD-OLED version it is slightly dimmer. The difference is not as significant as in last year’s F series, where the gap could reach as much as 500 nits. Here the parameters of both panels are very similar, and differences in peak brightness are only in the order of 100–150 nits. In small-area measurements the S90H on the WOLED panel easily reaches levels close to 1500 nits. Such a reserve of power allows HDR dynamics to be reproduced phenomenally; all highlights, light reflections and explosions have the necessary punch, exactly as the creators intended in the editing studio. As with most OLED displays, when a very bright scene fills the whole screen protection systems activate and brightness naturally falls to around 700 nits. It is worth emphasising that this is still an excellent result on the market. Often noticeably better than many Mini LED screens in the same segment.

Colour gamut coverage

The biggest difference between the two S90H variants lies in colour reproduction and saturation. This results directly from the different construction of the WOLED panel, which uses an additional white subpixel. As a consequence, colours at very high brightness do not reach the same intense saturation, and the volume of the wide gamut is somewhat more limited than in QD-OLED. That does not change the fact that in everyday use these differences will be hard for most viewers to spot. The DCI-P3 space we measured reaches nearly 99% on the WOLED panel, which means that in the vast majority of real film scenes both variants will present an almost identical picture. The true distance only reveals itself in rarer, exceptionally demanding productions that use the ultra-wide BT.2020 gamut. Due to the specifics of the WOLED panel’s construction, coverage of that standard is about 15% lower compared with the S90HAT with a QD-OLED panel, so the brightest, heavily lit colours in HDR may appear slightly less vivid.

We tested the LG G6 in the best factory mode in terms of colour fidelity, namely FILMMAKER MODE. In the case of our test unit, this mode was quite well tuned straight out of the box. In SDR content, the only issue we could point out was the white balance, which tended to drift towards warmer tones. Consequently, the image could occasionally appear slightly yellowed; however, overall, this was not an bothersome problem. The G6 performed a bit worse with HDR content. There, we noted too much blue component in the white balance, which caused the image to take on cooler hues, resulting in fairly noticeable errors. As can be seen in our ColorChecker chart, the colours indeed drifted towards these cooler registers. Nevertheless, considering the factory settings, the television displayed a perfectly decent level. We do know, however, that OLED screens – particularly those from LG – respond excellently to professional calibration, which is why we immediately went ahead with it.

In Filmmaker mode, which we strongly recommend switching on straight out of the box, the S90H offers very good factory colour tuning. Colours are natural and faithful to the creators' intent, without the irritating oversaturation found in more aggressive presets. However, as is often the case without full calibration, no two units are identical. In our test the white balance was slightly lacking in blue, causing the image to lean a little towards warmer, yellowish tones. This was most noticeable in bright scenes, such as the snowy sequences from Star Wars. Additionally, the gamma curve was slightly low at 2.2, which produced a minor lift in shadow detail. In HDR mode the tuning was somewhat better, showing only a slight undersaturation in the red region.

After professional calibration, we gained complete control over the panel, and we managed to align all parameters to nearly zero. We successfully calibrated the white balance perfectly, which eliminated the factory cool and warm tints from the screen. The effects are clear as day in the ColorChecker test – the average colour reproduction errors dropped below the critical value of 1-2. And what does that mean? PERFECT colours, without any distortion! However, as reviewers, we must point out here how the LG G6 arbitrarily manipulates brightness, for which the EOTF curve is responsible. When looking at the standard synthetic chart, it might seem that the line is quite straight. However, the situation changes when we turn on the measurement filter, which shows how the television interprets brightness in real, moving film scenes (EOTF in MOVIES). Then it becomes evident that some of the tiniest parts on the screen are slightly over-brightened by the algorithm. Of course, for the average viewer, such a deviation will be practically unnoticeable, but in the test of such an expensive screen, it is worth noting – especially since we are talking about a model that has huge aspirations to be named the best television of the year.

After a full calibration it’s fair to say the S90H in WOLED guise looks almost perfect. In SDR mode colour inaccuracies drop to ultra-low levels and Delta E values very rarely exceed 2. That’s a phenomenal result, so if you care about perfectly faithful colour reproduction it’s definitely worth considering calibration. The calibrated HDR mode also performs very well, with the white balance stabilised and earlier deviations eliminated. After professional fine-tuning it’s really hard to find anything to criticise, because the TV delivers an image with almost reference-level naturalness and three-dimensionality. The slightly lower score in this category compared with the QD-OLED variant is solely due to the aforementioned limitation in saturation in extremely bright scenes; the tuning options and colour fidelity themselves are at the highest level.

Whatever one may say about the G6’s problems with near-black signal, it must be fairly acknowledged that it handles heavily compressed material and lower resolution content exceptionally well. All unwanted, unsightly tonal transitions are effectively reduced here by the "Smooth Gradation" feature. At the "Low" setting, the algorithm works flawlessly – effectively masking the artefacts resulting from strong compression without destroying the sharpness and details in the frame. Higher levels of this function do indeed smooth the image further, but they start to blur the real elements of object texture, which is why we recommend keeping this slider at a low setting. As for the upscaling to 4K, the processor does an excellent job – edge sharpness and detail reconstruction are at the highest level, and in this regard, the G6 does not fall behind the world leaders at all.

In terms of posterisation reduction itself, Samsung has kept the solutions known from last year’s models. The dedicated gradient-smoothing function performs quite well and can effectively mask unwanted tonal banding, which is useful on a WOLED panel that is slightly more prone to banding. However, you should be aware of its aggressive behaviour. This mechanism, alongside the artefacts themselves, can clean up fine film grain and gently soften detail. Ultimately it is a matter of compromise, but if you want an absolutely faithful reproduction, it is safer to leave this option off.

Similarly, in the area of scaling it is difficult to call this a breakthrough. The S90H uses the same NQ4 Gen3 processor as its predecessor, so the upscaling quality was almost identical. The chip sharpens lower-resolution material very well, extracting a satisfying level of detail. Samsung still has not dealt with the longstanding overscan issue, though. With some older recordings or archive footage the edges of the image can be slightly cropped. It’s a minor flaw, but it’s a pity the manufacturer still hasn’t eliminated it.

LG G6 is an OLED television, so in the category of motion fluidity, it traditionally deserves the highest marks. The television supports very high refresh rates reaching up to 165 Hz in 4K resolution, but most importantly – on the screen, you will not notice any signs of blurring. The response time of the panel is almost instantaneous, ensuring that dynamic images remain perfectly sharp.

In terms of motion handling, the S90H is simply excellent. This year's panel offers a boosted refresh rate of up to 165 Hz, though in practice the benefit will mainly be for gamers connecting a high-end PC. For films, series or sports broadcasts such a high refresh rate makes no difference and the picture looks exactly the same as at the standard 120 Hz. Regardless of the source, however, the OLED panel's lightning-fast response time does its job, so motion is clean and the ghosting or smearing familiar from LCD screens simply does not occur here.

The LG G6 is a true monster for gamers and one of the best-equipped televisions on the market in this regard. The manufacturer has not skimped on features, equipping this model with as many as four full HDMI 2.1 ports with a maximum bandwidth of 48 Gbps. This means that no matter which port you plug in your PlayStation 5, Xbox Series X, or powerful PC, you will get the absolute maximum performance from them.

The television supports a full set of gaming technologies: from VRR (Variable Refresh Rate) to AMD FreeSync Premium Pro, and even Nvidia G-Sync Compatible. On top of that, it offers remarkably low, nearly imperceptible input lag and an exceptionally well-functioning Game Optimizer panel, which allows you to monitor signal parameters in real time. Gaming on this screen, with the perfect black of OLED and impressive refresh rates, is pure pleasure.

Players should feel at home with the S90H, because Samsung has left few reasons to complain in that respect. The TV has four HDMI 2.1 ports, each of which supports VRR, ALLM and high refresh rates. There’s also the Game Bar, a handy menu that lets you quickly check key parameters and change settings without leaving the game. Importantly, Samsung has also improved HGiG mode. In last year’s models it could cause problems when used with a console, but on the S90H it now works as it should. What really stands out against the competition is the Game Motion Plus feature. It’s a special motion smoothing mode for games that works best with titles running at 30 or 60 fps. Motion becomes noticeably smoother, while latency remains at a reasonable level. In our measurements it was under 50 ms, so gaming is still comfortable. That’s important, because on many TVs enabling a similar smoothing feature causes such a large increase in input lag that controls become noticeably sluggish. Samsung has managed to find a good compromise here. There’s still no Dolby Vision Gaming, but in practice Game Motion Plus may prove to be a much more useful feature.