LG OLED G6 (G64LW, G66LS) vs Samsung S90H (QD-OLED)

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.

The Samsung S90H is a genuinely bright TV for the mid-range OLED segment. In synthetic tests its peak brightness reached around 1650 nits. That’s an impressive result in this class, roughly 50% higher than what we have seen from previous models in this price bracket. Most importantly, these tests translate directly to real video material. In four out of five film clips we tested, the S90H’s brightness ranged between 1300 and 1500 nits. That headroom allows it to reproduce most HDR films with very high dynamic range and without obvious compromises, especially in material mastered to 1000–1500 nits. In practice light effects, reflections and explosions have the appropriate punch, and the picture does not appear dimmed. Of course, on full-screen very bright scenes the result is naturally lower and drops to around 900 nits. This is a direct result of the OLED panel’s protection systems working to prevent overload. Even in this scenario there is little to complain about. Those 900 nits across the whole screen is still a very high level, ensuring excellent dynamic range in HDR content.

Colour has always been a major strength of QD-OLED TVs, and the S90H is no exception. The DCI-P3 colour space we measured reached a full 100% (actually 99.9%), while coverage of the much wider BT.2020 gamut hit about 89%. That’s an excellent result, enabling very saturated and vivid colours in HDR content. It’s worth emphasising that QD-OLED’s advantage over WOLED panels is not limited to palette coverage alone. In practice it’s mainly visible in the higher brightness of saturated colours, that is in a greater colour volume. As a result, intense reds, greens and blues in HDR look more vibrant and more striking.

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.

The next stage of the test was to check how the S90H handles colour reproduction without any calibration. As always, we carried out the measurements in Filmmaker Mode, the best factory picture preset. And here Samsung really deserves praise. The factory tuning is at a very high level, and a few years ago this was not one of its strong points. The average colour error (Delta E) remained around 3, which is below the level at which most people can notice any inaccuracies. Only in the brightest shades of grey did the values slightly approach 4, but even then it's hard to regard this as a real problem while watching. For out-of-the-box settings, the result is simply excellent.

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.

All right, but you know we wouldn't be ourselves if we didn't also check how far we could push the S90H after professional calibration. And there was no big surprise. Since the factory settings were already very good, there wasn't much room for improvement. Even so, we managed to refine the picture to near perfection. After calibration the mean colour reproduction errors fell below the threshold of perception, with Delta E values under 2 for both SDR and HDR material. We also improved the brightness response, so the image more faithfully reflects the creators' intent and maintains appropriate tonality across the whole luminance range. After professional calibration the S90H therefore becomes a display very close to reference.

Will the difference be spectacular for everyone? Not necessarily. The factory settings already deliver a very high level, so in everyday viewing some people may not notice a dramatic jump. Much also depends on the individual unit. Our sample was very well tuned straight out of the box, but that doesn't mean every S90H will perform at the same level. Even identical models can differ from each other in terms of factory calibration. That's exactly why professional calibration makes sense: it allows a specific unit to be brought to the highest possible accuracy, rather than relying on a bit of luck when buying.

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 this respect Samsung has changed practically nothing compared with last year’s model, which is actually quite good news. The feature responsible for smoothing tonal transitions still very effectively limits the posterisation effect. However, you should remember that it works rather aggressively, because besides the artefacts themselves it can also remove film grain and slightly soften fine image detail. As always, this is therefore a matter of compromise and personal preference. If you want the most faithful reproduction of the source material possible, we recommend leaving this function turned off.

There is also little to be said about upscaling in terms of revolution. The S90H uses the same proprietary NQ4 Gen3 image processor as its predecessor, so scaling quality has remained practically unchanged. The TV handles lower-resolution material well, effectively improving its sharpness. However, the overscan problem has still not been solved. With some older material, especially archival recordings, it may happen that a portion of the image at the edges is cropped. It’s a minor flaw, but a shame Samsung has left this issue unchanged for another year running.

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 delivers a very high level. A new feature here is a panel with a refresh rate of up to 165 Hz, although in practice that will mainly benefit PC gamers. Films, series and sports broadcasts do not use such high refresh rates, so when watching them the difference compared with the standard 120 Hz will not be noticeable. That said, thanks to the OLED panel's lightning-fast response time motion is very clean and the picture does not suffer from the motion blur typical of many LCDs. Samsung has equipped the television with extensive motion-smoothness settings. You get two sliders: judder reduction and blur reduction, which let you easily tailor the picture's character to your own preferences. You can easily achieve a very smooth image when watching sport, but you can just as well preserve a more cinematic feel at the typical 24 frames per second. It all depends on which effect you prefer.

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.

From the outset the Samsung S90H feels like a TV designed with gamers in mind, and it's easy to see why. The manufacturer has equipped it with almost everything you could expect from a modern gaming screen. You get as many as four full-bandwidth HDMI 2.1 ports, support for ALLM and VRR, and very high refresh rates. There's also a clear Game Bar that lets you instantly check key picture parameters or change settings without leaving the game. Another very welcome improvement is the HGiG behaviour. Last year it could cause quite a few problems, but on the S90H it works exactly as it should.

Samsung's ace up its sleeve remains its proprietary Game Motion Plus mode. The feature works similarly to the motion smoothing used for films: it improves animation smoothness in games while keeping input lag at a very reasonable level. For titles running at 30 or 60 fps, with the right settings input lag did not exceed 40 ms in our tests. That's a very good result, especially since with many manufacturers enabling similar features results in delays several times higher. Game Motion Plus does not, of course, replace Dolby Vision Gaming, as it's a completely different type of feature, but overall it's a gaming addition that many players may find more noticeable. Smoother motion in 30/60 fps games often makes a bigger difference than HDR itself (which, incidentally, is often poorly implemented in games).