Does an unused high refresh rate screen still draw additional power?

[7412]

Hi.

 

I'm wondering: if my phone is able to reach 120hz, but I set it to 60 - will the superior nature of the screen still draw a bit more power than if it were a cheap 60hz screen instead?

Or does the software move of locking it at 60hz really nullify any extra battery consumption?

 

Thanks for your answers.

[Helpful Tech Witch]

it may draw more power than a cheeper screen, but it will draw about the same power as a screen pannel type, res, on a phone with the same hardware, but designed for 60hz

[mariushm]

We'd have to actually have access to the datasheets to tell you that.

I suspect that the screen could consume maybe 5-10% more power compared to a screen that's actually designed from the start for maximum 60 Hz.

[tkitch]

comparing two different phone screens is hard, but, yeah setting your phone to 60 is better on the battery than 120.

 

[TetraSky]

While it is certainly not double the power draw and it might be insignificant for most people, 120hz does use more power than 60hz on the same device. As such, if you set your phone to 60Hz instead of 120Hz, you do indeed save some battery life.

 

As people have tested this in the past concluded :

https://itigic.com/mobile-screen-consumption-of-120hz-vs-60hz/

the conclusion to the video itself, was that while the phone set at 60Hz still had 14% battery left, the one set at 120Hz was dead. Nearly a whole hour difference. So if you charge your phone every day, it likely doesn't matter at all.

[LogicalDrm]

-> Moved to Phones and Tablets

[Zodiark1593]

On 8/11/2021 at 12:49 PM, TetraSky said:

While it is certainly not double the power draw and it might be insignificant for most people, 120hz does use more power than 60hz on the same device. As such, if you set your phone to 60Hz instead of 120Hz, you do indeed save some battery life.

 

As people have tested this in the past concluded :

https://itigic.com/mobile-screen-consumption-of-120hz-vs-60hz/

the conclusion to the video itself, was that while the phone set at 60Hz still had 14% battery left, the one set at 120Hz was dead. Nearly a whole hour difference. So if you charge your phone every day, it likely doesn't matter at all.

Wonder what the core power draw is? I wouldn’t think the GPU would be the culprit, as drawing the UI is pretty trivial. The display itself seems probable. 

[7412]

On 8/14/2021 at 1:20 PM, huilun02 said:

In this scenario it is much simpler. Locking it to 60Hz does in fact save a considerable amount of power.

I know. My question is a bit more tricky.

Let's pick a fictional phone. It has 2 iterations: same design, same battery, same specs, same everything except the screen.

One is a 60hz screen, the other is a 120hz screen locked at 60hz.

Does the 2nd phone lose battery faster? Does the very nature of the screen draw more power even if the 120hz is disabled?

[mariushm]

It's tricky and complicated.

 

The actual lcd panel has some chips on it, which turn on and off each transistor that forms pixels on the screen. Those chips have some idle power consumption, and they may have to be more complex and run at higher frequencies internally in order to be able to update the pixels 120 times a second or more so these chips may use a bit more power doing it.

 

Now, because of this, they may consume a bit more power even if they receive only 60 updates a second through the input cable, or they may not. It could be that being a newer more modern chip it may have more features, it may have more power savings modes, or it may be able to do a screen update and then quickly switch to a "sleep" mode for 5-10ms until next frame comes, while older driver chips may use overall less power but not have those sleep features so at the end of the day they'd consume more.

 

Because 60 Hz/fps panels are so "old", the lcd panel maker may have ordered a few million pieces of a driver chip so your high end 1080p-1440p phone display may use driver chips designed 3-5 years ago, which are now super cheap and can do the job just fine at 60 updates per second, but the downside is they may made at a higher nm manufacturing process, which could mean a bit more idle power consumption, more leakage in the transistors in the silicon die, could mean less "smarts", less  power saving features etc.