Screen with QD-OLED in the test: Samsung’s new display technology is down

The editorial team received the first screen that uses a new QD OLED panel from Samsung. In this, the organic layers glow blue, and the color-converting nanoparticles replace the color filters on the red and green subpixels. OLEDs with quantum dot coating are likely to play a central role at Samsung in the coming years. First, though, you’ll find QD OLED panels in Sony smart TVs — and in computer monitors like the AW3423DW we tested.

Dell’s Alienware gaming monitor is equipped with a 34-inch QD OLED panel in 21:9 format with a resolution of 3440 x 1440 pixels. In our measurements and in the datasheet, the AW3423DW comes in very well:

  • Colors are saturated, especially green
  • Deep blacks and virtually unlimited contrast thanks to per-pixel dimming with OLED
  • Ultra-short switching times of 1.4ms on average – excellent for gaming
  • 175Hz and dynamic refresh rates with Nvidia’s G-Sync Ultimate or Adaptive-Sync (AMD FreeSync)
  • View HDR 400 true black

Unfortunately, a first look at the screen already reveals a glaring weakness of the QD-OLED: the AW3423DW displays all the high-contrast edges in color. This starts with typing, continues with Windows and ends with 3D games, like Signs or one of the many skyscrapers in the RPG “Cyberpunk 2077” when you look up at the sky. In the latter case, the screen had something of a built-in shallow chromatic aberration – although the effect is not as noticeable and annoying in a moving game as it is in a static desktop. However, the commission in its current form is essentially an issue of chaos.

The edges of the Alienware AW3423DW QD OLED display are unintentionally colored. Please note that the plate itself is sharp, but we took the photo with the focus shifted slightly so you don’t see each pixel individually.

(Photo: Mark Mantel / Heise Online)

The pixel arrangement is to blame: a pixel is made up of three sub-pixels in red, blue and green as usual, but arranged in a triangle rather than a single row. The red and blue subpixels are at the bottom, with the green pixel only in the middle at the top. The black gaps are very large and therefore each sub-pixel row can only appear green, while the other rows lack the green component.

The Alienware AW3423DW QD-OLED panel features an unusual triangular sub-pixel arrangement that results in vivid colors with high contrast edges.
(Photo: Benjamin Kraft/c’t)

In practice, this results in colored edges: with light areas on a dark background, horizontal edges are green on top and red-violet below, and with dark areas on a light background, the QD-OLED panel on the AW3423DW behaves the opposite. Darker color in dark areas and lighter in light areas produces less visible blue tones. In the case of vertical and sloping edges, color margins are more dependent on contrasts – from bright red, green, violet and blue, everything is included (see mouse pointer in the image above).

A look at the on-screen (OSD) menu proves that the problem is not due to low color downsampling, the launcher just sends thumbnail information to the screen. Even in the OSD with no driver connected, the white writing turned out to be in fact colored.

The Alienware AW3423DW begs the question if no one at Samsung (and later on Alienware) ever looked at the QD OLED display powered up during development. The manufacturer’s inquiry has not yet led to any knowledge of this.

The color effect was meant to be eye-catching – we were blown away the first time we turned it on. In the current form, we should advise against computer monitors with this panel and warn of upcoming TVs.

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That’s a pity, because the Alienware AW3423DW would otherwise be a successful monitor with great picture, fast OLED-typical response times, dynamic refresh rates over G-Sync Ultimate or Adaptive-Sync, and a reasonable price given other high-end gaming monitors, who still rely on LCD technology. The US model costs $1,300. Delivery in this country should start in the next few months.

(Photo: c’t)

When testing the Alienware monitor, we wondered if there was any quality control at all. The colored edges on the lighter edges are really unmistakable.

With this one screen, these artefacts don’t mean the end of the world – they weren’t quite as big as hoped. It looks very different for in-display panel technology, because QD-OLEDs could be a kind of hope for Samsung. The Korean group’s display division has almost abandoned its LCD technology in favor of organic quantum dot displays, and the consumer electronics division will also use QD-OLED in future TVs.

There will be almost no alternative for the next five years: LED displays that are tiny where the luminous pixels can’t be produced in the right size for living rooms or even offices at an affordable cost. Samsung also wants to use LG’s OLED panels with white sub-pixels in its TVs in the future. But Samsung didn’t want to see LG’s OLED panels as full 4K displays for a long time. So it can be difficult to present it to customers as a sophisticated solution.

We don’t know yet if Samsung’s upcoming QD OLED TVs will use the same pixel architecture as the panel in the Alienware display. However, the probability is high – and this will be a disaster. In screen testing, colored edges were also noticeable on bright edges in the video image, very clearly on high contrast edges, for example in subtitles or white scrolling text in motion picture credits. You are looking at the TV from a greater distance, which is probably why the color margin is not noticed. But for expensive models from the world’s largest consumer electronics maker, these handicrafts will still be off-limits. (United kingdom)


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