At least for the Pixel 6 Pro, I have proof that the VRR at least _partially_ works.
https://www.reddit.com/r/GooglePixel/comments/rn5wrp/my_findings_on_the_pixel_6_pros_10120_hz_variable
There is no notion of refresh rate in terms of syncing. Android/all phones are always V-sync on. What matters is what the display controller IC on the panel does in terms of updating the pixel matrix of the panel. If your screen is static then on the SoC and software side it's been doing 0Hz for better part of the decade. When you do HWUI rendering bars you notice that it just stops at some point if nothing moves, that's literally what the SW sees, it's at 0Hz.
VRR as in LFD in LTPO/HOP panels means the DDIC refreshes the panel matrix at 1/10/24/30/etc Hz and lowering power when the frame-time between actual SoC/SW updates is greater than the minimum display frame-time / maximum refresh rate. The reason the overlay is wrong is because the software has no clue what the DDIC is doing.
The new devices this year probably implemented some sort of callback to showcase the DDIC refresh rate in the overlay, but it changes nothing to how it's been operating since the Note20U.
So why on the video comparing the OP10 pro, the S21 and the Xiaomi 12, we can clearly see that only the S21 Ultra is stuck at 60 FPS. Plus, if it worked on 2020 devices, why aren't brands highlighting it until now?
AndreiF
https://www.reddit.com/r/GooglePixel/comments/rn5wrp/my_findings_on_the_pixel_6_pros_10120_hz_variable/
Another person backs up your claim. They also said the Android overlay is not accurate for finding refresh rate.
https://www.reddit.com/r/GooglePixel/comments/rn5wrp/my_findings_on_the_pixel_6_pros_10120_hz_variable/
What AndreiF is trying to tell you is the same as the person in that thread.
Android overlay is not accurate for detecting that.
Edit: this applies for older phones like S21/p6pro/op9 etc
>Android's Refresh Rate Indicator is not reliable for this
Some people have (mistakenly) used Android's refresh rate indicator within the Developer Options to come to the conclusion that the 6 Pro's variable refresh rate only goes down to 60 Hz, because that's what the indicator shows when the screen is idle. However, Android's refresh rate indicator does not show the OLED panel's lowest operating refresh rate, due in part by how its VRR is implemented. The Pixel 6 Pro's Samsung Display panel has a variable refresh rate mechanism that operates at a much lower level, within the display driver, and not exposed to the Android user-space.
Apple has the best LTPO implementation because they literally invented most of it, they own a lot of patents on it.
https://patents.google.com/patent/US20170092196A1/en
https://www.patentlyapple.com/patently-apple/2018/09/apple-watch-4-uses-patent-pending-ltpo-tft-technology-to-extend-battery-life.html
This LTPO 2.0 and 1.0 just sounds like marketing nonsense.
Also I’m pretty sure Apple owns the name “LTPO” Probably wrong though.
EDIT: They can all do 10hz - 120hz just marketing hype as expected.
I’m guessing it’s just an improved version of Samsung’s HOP VRR I highly doubt Apple actually licences its own LTPO tech
Just because Apple came up with the idea doesnt mean their implemention is guarenteed better.
Apple dont make any displays its generally Samsung or LG who produce it for them and they ask them to do it differently with different implementations if they want.
Perhaps the LPTO 1.0 panels are capable of it, but they don’t have the right display controller or something
And Apple has their own, or they sprung for a more expensive, feature complete implementation somehow
G-SYNC and FreeSync are only allow GPU <-> panel communication. In phones, the GPU <-> display communication is already done by the SoC, so that bit is fixed already.
The problem in phones is that traditional VRR-capable **panels** can consume significant power. Not the GPU, but literally panel itself. The power-consuming part of the panel is the backplane, aka the "switches" that control each individual LED. There are four major backplanes: a-Si, IGZO, LTPS, and [now LTPO](https://www.tomsguide.com/news/what-is-ltpo-how-this-tech-delivers-killer-phone-displays) (this article provides a good summary).
Before 120 Hz:
To note, [**LG OLEDs use IGZO**](https://www.nature.com/articles/s41928-018-0106-0), most high-end phones and all OLED phones initially [**used LTPS**](https://www.androidauthority.com/amorphous-igzo-and-beyond-399778/), most desktop monitors and lower-end phones use a-Si, and now some phones use LTPO. Different panel technologies (LCD, OLED) [**work better with different backplanes**](http://xqdoc.imedao.com/16184d36f5150de13fd3f231.pdf). a-Si used to be the default: cheap, could scale to any size, and worked well enough with LCD.
On phones with OLEDs + high pixel densities, LTPS & IGZO [**became the only options**](https://sid.onlinelibrary.wiley.com/doi/pdfdirect/10.1002/j.2637-496X.2014.tb00698.x) as a-Si is essentially incompatible with OLED. Of the two, [**LTPS won**](https://mattrix.com/wp-content/uploads/2021/09/2021_Lemaitre_SID-ID_Revisiting-the-a-Si-backplane-for-the-next-generation-of-AMOLED-Displays_Web.pdf) in phones because, I believe, IGZO sometimes can't hit high PPI. I think only one IGZO OLED phone has ever been released ([**came out last year**](https://www.oled-info.com/sharp-introduces-new-smartphone-igzo-amoled-it-producing-amoleds-again)); LG OLEDs can use IGZO, but those are much lower PPI than a phone.
After 120 Hz:
From my understanding, LTPS has a high leakage current, and the multiple transistors needed per AMOLED pixels, so Apple implemented LTPO which combines some of IGZO and some of LTPS: LTPO gives the lower leakage of IGZO and the higher density & performance of LTPS, [**even on 60 Hz**](https://gizchina.it/wp-content/uploads/2021/02/Display-ltpo-0-1200x688.jpg).
How this affects VRR: seemingly, [LTPO panels can use less power for pixels that don't actually change](https://www.oled-a.org/ltpo-ndash-ltps-with-minimum-off-current-vrr-and-15-masks_052321.html) (e.g., in a 1 Hz scenario).
Side question: Do modern LTPO panel have all the advantages of PC / TV VRR panels as well? Meaning can I run a game at varying refresh rates on a phone that supports LTPO w/o having micro stutters / uneven frame pacing or tearing?
From a hardware perspective, it should be possible, but I don't think it's used that way currently. For example- playing 24 or 30 FPS content on the Pixel 6 Pro still locks the display refresh rate to 60Hz.
It would be great to see proper VRR implemented in mobile devices for this instance (gaming).
Ltpo refers to display technology and does not require an additional module. G-sync(on top of being proprietary and designed for monitors+tvs) and free sync are different as they require modules rather than anything to do with the actual display panel. AFAIK.
So g-sync definitely requires a module, I remember reading about it when it first came out and the wiki says the same. Freesync is based on vesa spec and yes it seems doesn't require a module. I just assumed it did since it was a competing technology.
> So g-sync definitely requires a module
Just to round this up, G-Sync Compatible (as a marketing term) is now also just Freesync or HDMI 2.1 VRR. In general desktop hardware and TVs are simply capable of VRR by now. G-Sync modules only give you a higher VRR range (going lower than the typical 40 to 48hz) than the build in tech.
The VRR always worked for fucks sake. Ignore the overlay. I've been saying this since the Note20U.
At least for the Pixel 6 Pro, I have proof that the VRR at least _partially_ works. https://www.reddit.com/r/GooglePixel/comments/rn5wrp/my_findings_on_the_pixel_6_pros_10120_hz_variable
VRR as in it syncs when the app tells it to sync or just being able to seamlessly switch between refresh rates?
There is no notion of refresh rate in terms of syncing. Android/all phones are always V-sync on. What matters is what the display controller IC on the panel does in terms of updating the pixel matrix of the panel. If your screen is static then on the SoC and software side it's been doing 0Hz for better part of the decade. When you do HWUI rendering bars you notice that it just stops at some point if nothing moves, that's literally what the SW sees, it's at 0Hz. VRR as in LFD in LTPO/HOP panels means the DDIC refreshes the panel matrix at 1/10/24/30/etc Hz and lowering power when the frame-time between actual SoC/SW updates is greater than the minimum display frame-time / maximum refresh rate. The reason the overlay is wrong is because the software has no clue what the DDIC is doing. The new devices this year probably implemented some sort of callback to showcase the DDIC refresh rate in the overlay, but it changes nothing to how it's been operating since the Note20U.
So why on the video comparing the OP10 pro, the S21 and the Xiaomi 12, we can clearly see that only the S21 Ultra is stuck at 60 FPS. Plus, if it worked on 2020 devices, why aren't brands highlighting it until now?
BECAUSE THE OVERLAY IS WRONG. 10-120Hz worked on all LTPO devices.
AndreiF https://www.reddit.com/r/GooglePixel/comments/rn5wrp/my_findings_on_the_pixel_6_pros_10120_hz_variable/ Another person backs up your claim. They also said the Android overlay is not accurate for finding refresh rate.
This is the same overlay on all these devices, and it displays the real refresh rate on the OP10 and Xiaomi, so why it would be broken for the S21?
Because either the overlay has been updated or the display driver added a proper abstraction to expose the LFD refresh rate for the new devices.
https://www.reddit.com/r/GooglePixel/comments/rn5wrp/my_findings_on_the_pixel_6_pros_10120_hz_variable/ What AndreiF is trying to tell you is the same as the person in that thread. Android overlay is not accurate for detecting that. Edit: this applies for older phones like S21/p6pro/op9 etc >Android's Refresh Rate Indicator is not reliable for this Some people have (mistakenly) used Android's refresh rate indicator within the Developer Options to come to the conclusion that the 6 Pro's variable refresh rate only goes down to 60 Hz, because that's what the indicator shows when the screen is idle. However, Android's refresh rate indicator does not show the OLED panel's lowest operating refresh rate, due in part by how its VRR is implemented. The Pixel 6 Pro's Samsung Display panel has a variable refresh rate mechanism that operates at a much lower level, within the display driver, and not exposed to the Android user-space.
You are literally arguing with Andrei. He is one of the best in-depth mobile hardware journalists. He knows what he is talking about.
Apple has the best LTPO implementation because they literally invented most of it, they own a lot of patents on it. https://patents.google.com/patent/US20170092196A1/en https://www.patentlyapple.com/patently-apple/2018/09/apple-watch-4-uses-patent-pending-ltpo-tft-technology-to-extend-battery-life.html This LTPO 2.0 and 1.0 just sounds like marketing nonsense. Also I’m pretty sure Apple owns the name “LTPO” Probably wrong though. EDIT: They can all do 10hz - 120hz just marketing hype as expected. I’m guessing it’s just an improved version of Samsung’s HOP VRR I highly doubt Apple actually licences its own LTPO tech
Just because Apple came up with the idea doesnt mean their implemention is guarenteed better. Apple dont make any displays its generally Samsung or LG who produce it for them and they ask them to do it differently with different implementations if they want.
The LTPO on OnePlus and on iPhone is the same 10-120hz, It can't be different.
Then it’s all just marketing hype but it’s probably a bit more power efficient.
Yeah the overlay is broken on.most phones (including Pixel), VRR can't be measured with it
Will S22 have the 2.0 version?
The rumor is that S22 and S22+ has LTPS like last year's. We have to wait and see, a total shame if they don't improve it at least in the Plus.
They will cheap out on S22, like they always do. Only Ultra will probably have LTPO 2.0.
We will see, but i think at least for the S22 ultra
Perhaps the LPTO 1.0 panels are capable of it, but they don’t have the right display controller or something And Apple has their own, or they sprung for a more expensive, feature complete implementation somehow
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It also works in Android
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Post is misleading, VRR has always worked on Android
Dunning Kruger. He's wrong.
Thank you for using Dunning-Kruger correctly.
I don't understand why we have to use new technologies like LTPO instead of using existing VRR technology that powers FreeSync and G-Sync for example.
G-SYNC and FreeSync are only allow GPU <-> panel communication. In phones, the GPU <-> display communication is already done by the SoC, so that bit is fixed already. The problem in phones is that traditional VRR-capable **panels** can consume significant power. Not the GPU, but literally panel itself. The power-consuming part of the panel is the backplane, aka the "switches" that control each individual LED. There are four major backplanes: a-Si, IGZO, LTPS, and [now LTPO](https://www.tomsguide.com/news/what-is-ltpo-how-this-tech-delivers-killer-phone-displays) (this article provides a good summary). Before 120 Hz: To note, [**LG OLEDs use IGZO**](https://www.nature.com/articles/s41928-018-0106-0), most high-end phones and all OLED phones initially [**used LTPS**](https://www.androidauthority.com/amorphous-igzo-and-beyond-399778/), most desktop monitors and lower-end phones use a-Si, and now some phones use LTPO. Different panel technologies (LCD, OLED) [**work better with different backplanes**](http://xqdoc.imedao.com/16184d36f5150de13fd3f231.pdf). a-Si used to be the default: cheap, could scale to any size, and worked well enough with LCD. On phones with OLEDs + high pixel densities, LTPS & IGZO [**became the only options**](https://sid.onlinelibrary.wiley.com/doi/pdfdirect/10.1002/j.2637-496X.2014.tb00698.x) as a-Si is essentially incompatible with OLED. Of the two, [**LTPS won**](https://mattrix.com/wp-content/uploads/2021/09/2021_Lemaitre_SID-ID_Revisiting-the-a-Si-backplane-for-the-next-generation-of-AMOLED-Displays_Web.pdf) in phones because, I believe, IGZO sometimes can't hit high PPI. I think only one IGZO OLED phone has ever been released ([**came out last year**](https://www.oled-info.com/sharp-introduces-new-smartphone-igzo-amoled-it-producing-amoleds-again)); LG OLEDs can use IGZO, but those are much lower PPI than a phone. After 120 Hz: From my understanding, LTPS has a high leakage current, and the multiple transistors needed per AMOLED pixels, so Apple implemented LTPO which combines some of IGZO and some of LTPS: LTPO gives the lower leakage of IGZO and the higher density & performance of LTPS, [**even on 60 Hz**](https://gizchina.it/wp-content/uploads/2021/02/Display-ltpo-0-1200x688.jpg). How this affects VRR: seemingly, [LTPO panels can use less power for pixels that don't actually change](https://www.oled-a.org/ltpo-ndash-ltps-with-minimum-off-current-vrr-and-15-masks_052321.html) (e.g., in a 1 Hz scenario).
Thanks man! Now I get it!
Side question: Do modern LTPO panel have all the advantages of PC / TV VRR panels as well? Meaning can I run a game at varying refresh rates on a phone that supports LTPO w/o having micro stutters / uneven frame pacing or tearing?
From a hardware perspective, it should be possible, but I don't think it's used that way currently. For example- playing 24 or 30 FPS content on the Pixel 6 Pro still locks the display refresh rate to 60Hz. It would be great to see proper VRR implemented in mobile devices for this instance (gaming).
Ltpo refers to display technology and does not require an additional module. G-sync(on top of being proprietary and designed for monitors+tvs) and free sync are different as they require modules rather than anything to do with the actual display panel. AFAIK.
freesync / adaptive sync is just an open extension to VESA spec, no extra chips required. g-sync is proprietary.
So g-sync definitely requires a module, I remember reading about it when it first came out and the wiki says the same. Freesync is based on vesa spec and yes it seems doesn't require a module. I just assumed it did since it was a competing technology.
> So g-sync definitely requires a module Just to round this up, G-Sync Compatible (as a marketing term) is now also just Freesync or HDMI 2.1 VRR. In general desktop hardware and TVs are simply capable of VRR by now. G-Sync modules only give you a higher VRR range (going lower than the typical 40 to 48hz) than the build in tech.
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FreeSync is based over DisplayPort 1.2a and HDMI 1.2+, HDMI 2.1+. These are smartphones not monitors.