Asus Zenbook Duo review (dual-display 2025 model, Intel Core Ultra 9 285H)

6 Comments

  1. NikoB

    February 14, 2025 at 10:50 pm

    Andrei, there is a technical error in the description. On the Asus website:
    https://www.asus.com/laptops/for-home/zenbook/asus-zenbook-duo-2024-ux8406/techspec/
    they claim that the screen panels have received Display HDR True Black 500 certification, not Display HDR 500, which is not stated in your review (not once), which should guarantee no more than 0.0005 nits of black level according to VESA certification.

    But then comes the most interesting part (I have already noticed this on a number of websites).
    On the Panelook website, there is no 14" version of the panel indicated to you, but there is a whole family of this series, for example this one
    https://www.panelook.com/ATNA40CU10-0_Samsung_14.0_OLED_overview_66978.html
    I specifically gave a link to an analog in advance. Moreover, there is also an older ATNA40CU06-0 – there is practically no difference in black level. And version 09 clearly does not stand out against their background.

    You indicated that the black level is 0 nits in the review (like infinite contrast), on this website:
    https://laptopmedia.com/screen/atna40cu09-0-sdc419d/
    it is also indicated that there is supposedly 0 nits of black level.

    Which of course is completely wrong. In fact, apparently both their and your calibrator are simply not capable of measuring the black level below 0.01 nits. Because according to the direct analogs indicated above on the Panelook website, they have the manufacturer itself specifies a typical contrast of 100k:1 in the datasheet. We divide 400-500 nits by 100K and get, in the best case, 0.004-0.005 nits of the minimum black level, which a calibrator designed for professional measurements of AM (OLED) panels with a True Black HDR nameplate must immediately catch as unacceptable, because the accuracy of the calibrator must be obviously higher than 0.0001 nits, right? So that there is a sufficient confidence interval?

    That is why I am concerned about all these measurements and the possible fraud with the real black level (in complete darkness), because the question arises how ASUS (and others) issue such certificates of conformity, if the panel manufacturers themselves clearly write that the typical contrast there is 100K:1, and not the one required for this certificate, with a peak brightness of 500 nits. minimum 1M:1.

    There is something clearly wrong here, either with the measurements or the integrity of the issuance of certificates from VESA. Why do panel manufacturers write a typical contrast 10 times lower than required for this True Black HDR certification, i.e. 1M:1 typical? They are clearly insuring themselves against accusations if someone actually undertakes to check all these statements with an ultra-precise calibrator with a minimum scale division of 0.0001 nits, at least.

    And all this directly affects the real ability to display HDR10 content. In this case, if the real contrast is 100k:1 and the black level is 0.005 nits, respectively, then there will be a lack of gradations somewhere, because the requirement of 0.0005 nits is not just like that, but to ensure linear step accuracy in 30-bit color depth (although for 4k, 36-bit color is more likely needed for perfectly smooth gradients) – apparently so …

    • Andrei Girbea

      February 17, 2025 at 1:05 pm

      Niko, we don't have the tools to test black levels at that precision. I also don't have enough expertise on this matter to make any claims on that certification.

      I know this is something that matters to you, based on your previous comments, but I don't know how important this is for most people on this sort of a 14-inch laptop screen. I mean, are you really realistically going to play HDR content on a 14-inch laptop screen and are your eyes able to distinguish differences of fraction of nits in black levels?

      • Piotr

        February 21, 2025 at 10:35 pm

        If it's the same "NikoB" as on notebookcheck, he will just start nitpicking whatever element and looking for conspiracies in benchmarking.

      • NikoB

        February 25, 2025 at 9:34 pm

        Some people may believe these declarations. How can they believe that it really has an HDMI 2.1 port (full version, without understanding the nuances and also with DP2.0+ – for example, Intel has now started writing in the Arrow Lake datasheet that HDMI 2.1 with FRL, but this means nothing, since the maximum mode number is not specified – it should be 6). And some people still naively believe that they receive a signal to monitors without losses in a number of modern 4K high-frequency monitors (with a channel cut to 24 Gbps via HDMI 2.1). And the task of reviews is precisely to point out the muddy and narrow points in the official declarations of manufacturers, isn't it?

        The human eye will notice the difference – in dynamics. That's when everything becomes bad with smooth gradient fills (sunrise, sunset, etc.).

        The fact itself is important – the datasheets indicate a typical contrast 10 times lower than the one promised by Asus, because it claims to have received the specified certificate of conformity, guaranteeing a maximum black level of no more than 0.0005 nits according to the description on the VESA consortium website – https://displayhdr.org – there is a full table there. Isn't this a reason for an investigation? If there is an error in my reasoning somewhere, then that is another matter, but I do not see it.

        And whether this matters is up to the buyer to decide. My task is only to draw attention to this. After all, the buyer decides whether the product is worth the stated price, believing in the manufacturer's declarations, regarding his personal preferences and requirements.

  2. will blake

    February 25, 2025 at 10:07 am

    Kinda disagree with you about "..significant premium over a regular.." BAD. Can't see it. You know, i'd pay premium for a laptop and a portable monitor with the same panel in it (heck, even just same resolution and brightness). In my case, 16-17 inches with fastest low power CPU and i'd also pay premium for uber class cooling which makes the thing silent. If this z-book design is useful for somebody, it's totally worth a"premium".

    • NikoB

      February 25, 2025 at 9:48 pm

      The less mass series (in demand), the more expensive it is in terms of production costs. There are already more than 8 billion people on the planet. Now it is not very difficult to find at least 1 million buyers for almost everything, even completely strange products from the point of view of other layers of buyers. It is only a question of price. Sometimes some models are made simply for the prestige of the brand and to increase its recognition in the world, without any hope for mass demand. Sometimes successful engineering and design solutions are found, they become solutions for mass series, and sometimes they are not. It is like formula 1.

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