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LG's new 1Hz display is the secret behind a new laptop's battery life

pcworld.com

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Re: LG's new 1Hz display is the secret behind a new laptop's battery life

#151

Post by 01HNNWZ0MV43FF »

TeMPOraL wrote: post #120
WhyNotHugo wrote: post #114

Earlier quoted context omitted.

PSR (panel self-refresh) lets you send a single frame from software and tell the display to keep using that. You don’t need to render 60 times the same frame in software just to keep that visible on screen.

How often is that used? Is there a way to check? With the amount of bullshit animations all OSes come with these days, enabled by default, and most applications being webapp with their own secondary layer of animations, and with the typical developer's near-zero familiarity with how floating point numbers behave, I imagine there's nearly always some animation somewhere, almost but not quite eased to a stop, that's ma…

Android has a debug tool that flashes colors when any composed layer changes. It's probably an easy optimization for them to not re-render when nothing changes.

Re: LG's new 1Hz display is the secret behind a new laptop's battery life

#152

Post by alok-g »

KolibriFly wrote: post #138
alok-g wrote: post #87

Earlier quoted context omitted.

I used to be a display architect about 15 years back (for Qualcomm mirasol, et al), so my knowledge of the specifics / numbers is outdated. Sharing what I know. High pixel density displays have disproportionately higher display refresh power (not just proportional to the total number of pixels as the column lines capacitances need to be driven again for writing each row of pixels). This was an important concern as hi…

What's interesting about these newer 1Hz claims is that they're basically trying to sidestep the exact problems you mention

Correct.

I myself have been privy to similar R&D going on for more than a decade.

Re: LG's new 1Hz display is the secret behind a new laptop's battery life

#153

Post by 01HNNWZ0MV43FF »

Veedrac wrote: post #75
qnleigh wrote: post #32

> That will help save enormous amounts of power: up to 48 percent on a single charge, Why does refresh rate have such a large impact on power consumption? I understand that the control electronics are 60x more active at 60 Hz than 1 Hz, but shouldn't the light emission itself be the dominant source of power consumption by far?

I think the idea is that in an always-on display mode, most of the screen is black and the rest is dim, so circuitry power budget becomes a much larger fraction of overhead.

Ohh like property tax on a vacant building

Re: LG's new 1Hz display is the secret behind a new laptop's battery life

#154

Post by cromka »

KolibriFly wrote: post #137

Sure dropping toward 1Hz could be huge. But the moment you scroll, watch video, or even have subtle UI animations, you're back in higher refresh territory

How is this a but? This is exactly what you want: the screen refreshes only when a new content appears or once a second.

Re: LG's new 1Hz display is the secret behind a new laptop's battery life

#155

Post by youknownothing »

I'm guessing that for this to work you need to be able to selectively refresh parts of the screen at different rates? a 1Hz refresh rate would be rubbish just to follow the mouse cursor, so at least that part of the screen needs to refresh faster. However, it does make sense for the parts of the screen that are mostly static. Looking at my screen as I type this, the only part that needs a high-refresh rate is the text-box where I'm typing (I can type several keys per second so I wouldn't want a refresh rate of 1 Hz). However, the rest of the screen is not changing at all so a slow refresh is perfectly fine.

Re: LG's new 1Hz display is the secret behind a new laptop's battery life

#156

Post by elif »

youknownothing wrote: post #155

I'm guessing that for this to work you need to be able to selectively refresh parts of the screen at different rates? a 1Hz refresh rate would be rubbish just to follow the mouse cursor, so at least that part of the screen needs to refresh faster. However, it does make sense for the parts of the screen that are mostly static. Looking at my screen as I type this, the only part that needs a high-refresh rate is the tex…

You're not moving your mouse 100% of the time. Probably less than 25% of the time. Probably using your keyboard less than 25% of the time. It doesn't need to degrade experience OR selectively refresh part of the screen (which it certainly doesn't).

Re: LG's new 1Hz display is the secret behind a new laptop's battery life

#157

Post by elif »

qnleigh wrote: post #32

> That will help save enormous amounts of power: up to 48 percent on a single charge, Why does refresh rate have such a large impact on power consumption? I understand that the control electronics are 60x more active at 60 Hz than 1 Hz, but shouldn't the light emission itself be the dominant source of power consumption by far?

Your GPU rendering 1 frame vs your GPU rendering 60 frames.

Re: LG's new 1Hz display is the secret behind a new laptop's battery life

#158

Post by TZubiri »

Modern software regularly takes like 1 second to load anyways. 200ms is the minimum human reaction time, so adding 100ms would only add like 50% to the REPL user interaction. Something like 10Hz might be quite usable while minimally contributing to lag.

The idea of having a 60Hz screen is nice, but in practice it turns out that display refresh rate is not the bottleneck for most software.

Re: LG's new 1Hz display is the secret behind a new laptop's battery life

#159

Post by saltcured »

alok-g wrote: post #150
thisislife2 wrote: post #128

Earlier quoted context omitted.

Since you are knowledgable about this, do you have any idea what happened to Mirasol technology? I was fascinated by those colour e-paper like displays, and disappointed when plans to manufacture it was shelved. Then I learnt Apple purchased it but it looks more like a patent padding purchase than for tech development as nothing has come out of it form Apple too. Is it in some way still being developed or parts of it…

Being a key technology architect for it (not the core inventor), I know all about it, and then some more! I cannot however talk publicly about it. :-( It has been a disappointment for me as well. I had worked on it for nearly eight years. The idea was so interesting--using thin-film interference for creating images is akin to shaping Newton's rings into arbitrary images, something which even Newton would not have ima…

My fantasy display would be some kind of reflective-mode display that can passively show static images like e-ink, have partial updates like MIP LCD in wearables, response times like modern LCD and AMOLED, and "super-real" contrast/gain.

I.e. actually do wavelength conversion to not just reflect a narrow-pass filtered version of the ambient light, but convert that broad spectrum energy into the desired visuals, so it isn't always inherently dimmer than the environment. I can only imagine this being either:

1. some wild materials science stuff that manages interference

2. some wild materials science stuff that controls multi-photon fluorescence

3. some wild materials science stuff to fuse photoelectric and electroemissive functions in the same panel. i.e. not really passive but extremely low loss active system to double-convert the ambient light that can follow the power curve of available light

Re: LG's new 1Hz display is the secret behind a new laptop's battery life

#160

Post by snailmailman »

bracketfocus wrote: post #28
nmstoker wrote: post #27

Sorry, might be obvious to some, but is that rate applied to the whole screen or can certain parts be limited to 1Hz whilst others are at a higher rate? The ability to vary it seems like it would be valuable as there are significant portions of a screen that remain fairly static for longer periods but equally there are sections that would need to change more often and would thus mess with the ability to stick to a lo…

From what I understand, the laptop will reduce the refresh rate (of the entire display) to as low as 1Hz if what is being displayed effectively “allows” it. For example: - reading an article with intermittent scrolling - typing with periodic breaks

I think windows has a feature built in on some adaptive refresh rate displays to dynamically shift the frame rate down (to 30, on my screen) or up to the cap, depending on what’s actually happening.

I remember playing with it a bit, and it would dynamically change to a high refresh rate as you moved the mouse, and then drop down as soon as the mouse cursor stopped moving.

I had issues with it sometimes being lower refresh rate even when there was motion on screen, so the frame rate swings were unfortunately noticeable. Motion would get smoother for all content whenever the mouse moved.

1hz is drastically fewer refreshes. I hope they have the “is this content static” measurement actually worked out to a degree where it’s not noticeable.

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