This generation of Samsung flagship devices in the Galaxy S21 series is completely different from recent years, as Samsung has chosen to create a much more unequal device series between the ‘standard’ Galaxy S21, S21 + and the larger, more feature-laden Galaxy S21 Ultra.
In addition to the cameras and the overall form factor, the screen where the Galaxy S21 Ultra differs significantly from its siblings. This is not only thanks to the cheaper siblings who prefer to downgrade to FHD resolution panels, but also because the S21 Ultra generally uses a brand new OLED screen that pushes the boundaries in terms of technology.
QHD at 120Hz, finally, but still limited VRR
One of the major changes in the capabilities of the S21 Ultra screen is the ability to finally run the screen at its original resolution of 1440 x 3200 at 120Hz – an option not previously possible on the S20 or Note20 series devices was not.
Samsung’s way of making this possible is relatively simple and in line with what we saw in the OnePlus 8 Pro last year: the MIPI interface clock has been increased from 1157MHz to 1462MHz. It’s still a single 4 – lane interface in terms of width, but just like on the 8 Pro, the increased frequency provides sufficient bandwidth to now enable the high refresh rate at high resolution.
The panel of the S21 Ultra, like the Note20 Ultra, uses a new hybrid oxide and polycrystalline backplate technology that is approximately equivalent to LTPO display technologies, enabling it to enable low refresh rates and seamless switching between refresh rates .
We covered this new VRR (variable refresh rate) in detail in our Note20 Ultra screen analysis and how it works transparently for the hardware, and how the LFD (low frequency drive) can achieve great benefits for power efficiency. “Customizable” screen refresh rate mode.
In this regard, the Galaxy S21 Ultra behaves the same as the Note20 Ultra. It should be noted that this also includes that the behavior of the VRR mechanism is not functional in low brightness situations, with power consumption varying depending on what the ambient light sensor of the phone picks up. This means that the VRR and LFD apparently work as intended in brighter situations where the ambient light sensor detects the brightness of more than 40 lux.
The Galaxy S21 Ultra which now allows QHD at 120Hz means we have 2 additional working modes for the screen compared to the way the Note20 Ultra managed things:
At the 60Hz QHD resolution, the basic power consumption of the S21 Ultra (an Exynos 2100 variant in this context) uses 469 to 481mW of power on a completely black screen in terms of the total power of the device. Similar to the Note20 Ultra, we see that there is still a kind of VRR / LFD that works in the 60Hz mode, because the screen will consume less power in brighter environmental situations, although the delta here is less than what we have on the Note20 Ultra.
At 120Hz FHD, the same modes of operation as possible on the Note20 Ultra, for some reason the S21 Ultra looks 130mW more and ends up at 558mW above 428mW of the Note20 Ultra. I’m not sure if we see the bigger difference between the devices, but we’m talking about different DDICs and different panels, as well as different SoCs.
The S21 Ultra compares very well here with the Snapdragon S20 Ultra, and uses about 200 mW less power, although the difference to the Exynos S20 Ultra at about 45 mW is not that great.
Unfortunately, the big catch on Samsung’s VRR / LFD mechanism is the same as on the Note20 Ultra, as the power-saving mechanisms are no longer in the environmental state below 40 lux, and the phone consumes a lot. , similar to what we saw on the Snapdragon S20 Ultra last year.
If you use your phone in dark or even dim conditions, the variable refresh rate does not work at all, and the 120Hz mode has a huge cost of 300 mW at baseline power. Because the screen generally uses less power in such conditions, because I assume it works at a lower brightness level, this base effect is a very large percentage of the total power consumption of the device.
I was not a big fan of this aspect of the Note20 Ultra and previous generation 120Hz implementations – I wish Samsung, instead of switching off the VRR / LFD under dim conditions, would simply switch to 60Hz mode, because it would be a much more efficient alternative. Of course, the best solution would be to simply get rid of this limited brightness limitation and allow 120Hz and VRR in all conditions. It’s still not exactly clear about the technical reason why Samsung uses this limitation in the first place, as I ‘I do not see a difference in screen quality at all if you mislead the surrounding brightness sensor of the phone and it between VRR / Switch LFD on and off.
A New OLED Emitter Generation – Huge Leaps
While the QHD 120Hz and VRR / LFD technology are interesting, they are not exactly the latest technologies, although Samsung is finally bringing it to the Galaxy S series (at least the Ultra).
The most interesting part of the Galaxy S21 Ultra screen is the fact that it is the first to use a new generation OLED emitter. Over the years, there have been noticeable jumps in OLED power efficiency, and most of them have been linked to the introduction of new generation of emitters that have improved their predecessors. Samsung does not really talk much about the technical descriptions of these issuers or their generation designation, but the S21 Ultra is such a new generation.
To measure the difference between the screen generations, we simply measure the power consumption of the different devices at different brightness levels, and we compare the new Galaxy S21 Ultra with the previous generation S20 Ultra, as well as using the Note20 Ultra as extra data throw. -point:
Immediately we can see that the new S21 Ultra has a big difference in the brightness ability as well as the power consumption. The different devices start at about the same base point starting point for power consumption on a full black screen: 481mW for the S21 Ultra, 510mW for the S20 Ultra and 476mW for the Note20 Ultra. We measure things in 60Hz mode because we only focus on the brightness power of the screens.
Compared to the S20 Ultra, with 200 and 400 nets, the S21 Ultra is about 22% more efficient when displayed in full screen. This is actually a large number, as we are measuring the total power of the device, not just the screen.
If we normalize the power curve to the baseline power, the S21 Ultra is actually even more efficient – 26% to 31%, depending on the brightness level.
While the new S21 Ultra screen is the brightest Samsung has ever delivered, reaching white levels of up to 942 only at full screen, it uses less power than the S20 Ultra’s 778-just-peak brightness. The peak power is also 20% lower than the Note20 Ultra, although it is also brighter with 31 nets.
It’s interesting to see the S20 Ultra versus the Note20 Ultra power curves here – the two roughly agree with about 150 nets, after which the Note20 Ultra takes the lead, but the advantage here seems more established in terms of absolute mW, as the power curves still run parallel to each other – probably due to the increase in efficiency due to the new backplane technology of the Note20 Ultra. However, the power curve of the S21 Ultra is clearly more diverse with the increase in brightness levels, which is a sign of improved brightness efficiency as opposed to the efficiency of the panel drive, which is exactly what we would expect with the new emission technology.
Instead of demonstrating power in an unrealistic white screen on the full screen, we take something with a more realistic average image level, such as the AnandTech homepage:
S21 Ultra and S20 Ultra
The scenario here is both the S21 Ultra and S20 Ultra next to each other, set to 120Hz FHD, calibrated to 300 nits brightness, and under brighter lighter conditions to activate the S21 Ultra’s VRR / LFD mechanisms.
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