We’ve already heard that Samsung Display is preparing to start manufacturing Galaxy S27 displays soon. This may have already happened; therefore, these new leaks could be perfectly plausible. Apparently, the S27 Pro and S27 Ultra will be the first Samsung smartphones to offer DC dimming. It seems impossible, and yet a quick search later – indeed, even the Galaxy S26 Ultra relies on traditional PWM to adjust its brightness.
To simplify things a bit, in case you don’t know what we’re talking about, PWM (Pulse width Modulation) is the traditional way of adjusting the brightness of a display. Basically, it turns the light source (the backlight or the pixels themselves in auto-emitting display technology) on and off very quickly to achieve a different perceived brightness. It works, but it’s a sort of “hack” that relies on how our eyes work, and some people are actually quite sensitive to the technique and can suffer from eye strain and even headaches. The solution we have is DC dimming. It actually adjusts the input voltage of the light source, so no nasty flickering. However, this is much more difficult to do, especially on modern displays with other features such as variable refresh rate.
This doesn’t mean it’s impossible, just difficult. Open, for example, a recent spec sheet of a flagship Xiaomi device, and you’ll instantly spot the adaptive refresh rate with LTPO technology and optional DC dimming. This remains a technological hurdle, as we’ve said, and often requires a hybrid approach in which medium to high brightness levels use DC while low brightness levels switch to PWM. Yet it can be done, and it is largely for the benefit and comfort of the user.
Anyway, more to the point, a rumor has surfaced that the S27 Pro and S27 Ultra will finally feature DC dimming. At least to some extent, since a hybrid approach might still be necessary. This is apparently another thing that’s part of the larger “split” of the S27’s screen. According to sources, the Pro and Ultra will get Samsung’s latest M16 OLED material formula, while the regular S27 and S27 Plus will get the M14+. Another display differentiator is also the Privacy Display feature, introduced in the Galaxy S26 Ultra. Apparently it remains on the S27 Pro and S27 Ultra.
Frankly, it’s quite surprising that Samsung is keeping the frankly specialized Privacy Display feature, which is quite complicated from a hardware perspective and seems like a much bigger investment than switching to DC dimming. And while we’re on the subject, we don’t want to sound like we don’t appreciate the potential addition, but where is the proper hardware support for 10-bit color? Some competitors already offer 12-bit color.
Before we light up the comments section, let’s see how economics of scale works both ways and that in incredibly high-volume models, saving even just a few cents makes huge sense. And, just to keep things as balanced as possible, it’s not like Samsung is the “greedy villain” here. Apple iPhones don’t really have DC dimming either. They have a “smooth PWM” mode in the settings. And there’s no 10-bit hardware color on iPhones either. So if you want to be mad at someone, it should probably be the “big guys”.
Source
Gn tech
