Comment by jerlam

5 days ago

Haven't phones, watches and tablets been using low refresh rates to enable battery improvements for a while?

The Apple Watch Series 5 (2019) has a refresh rate down to 1Hz.

M4 iPad Pro lacks always-on display despite OLED panel with variable refresh rate (2024):

https://9to5mac.com/2024/05/09/m4-ipad-pro-always-on-display...

Phones and watches do that with LTPO OLED which I don't believe exists at higher screen sizes although I'm not sure why. This is supposed to be special because it isn't OLED so should be able to get brighter and not have to worry about burn in.

Dell needs to sell these XPS. The AI button doesn't do the trick, so battery life may do it.

  • What's the real-world battery life though? My mac gets 8 hours real world; 16 in benchmarks; 24 claimed by apple.

    Assuming the xps has the same size battery, and this really reduces power consumption by 48%, I'd expect 16 hours real world, 32 in benchmarks and 48 in some workload Dell can cherry pick.

    • Both my last two XPSes have had shit battery life. Maybe 3.5h when new and only 2h after a few months of use. They also experience a lot of thermal throttling (i7 12700h, 9750h) and newer updates have removed the option of undervolting which used to fix that.

      Positive is that the battery life couldn't possibly get worse with newer ones.

      1 reply →

    • I put my MBP in low power mode when using the battery and I get easily 12-15 hours with my full dev environment running.

OLED iPad dont have always on because of burn-in. Considering people certainly use it as photo frame, notification and time daahboars, kitchen recipe book, etc.

Less of a problem for iphones that unlikely to stay for a week in the same place plugged in and unused.

  • I don't think many people are spending $1k on an iPad Pro, the only iPad with OLED, to use as a picture frame.

    • They dont buy it for this purpose. Its just end up like that for a lot of people I know since it just weird device between iphone and macbook that end not being used for much.

      4 replies →

>M4 iPad Pro lacks always-on display despite OLED panel with variable refresh rate (2024):

Brightness, Uniformity, Colour Accuracy etc. It is hard as we take more and more features for granted. There is also cost issues, which is why you only see them in smaller screens.

iPad Pro only goes down to 10 FPS. This may be the display of the upcoming MacBook Pro.

Panel Self Refresh should largely just work, and I believe has been on laptops for a long long time. Here's Intel demo'ing it in 2011. https://www.theregister.com/2011/09/14/intel_demos_panel_sel...

I'm not sure that there's really anything new here? 1Hz might be lower. Adoption might be not that good. But this might just be iteration on something that many folks have just not really taken good advantage of till now. There's perhaps signficiant display tech advancements to get the Hz low, without having significant G-Sync style screen-buffers to support it.

One factor that might be interesting, I don't know if there's a partial refresh anywhere. Having something moving on the screen but everything else stable would be neat to optimize for. I often have a video going in part of a screen. But that doesn't mean the whole screen needs to redraw.

  • I’m not an expert here, but …

    CRTs needed to be refreshed to keep the phosphors glowing. But all screens are now digital: why is there a refresh rate at all?

    Can’t we memory-map the actual hardware bits behind each pixel and just draw directly (using PCIe or whatever)?

    • I think you're assuming that LCDs all have framebuffers, but this is not the case. A basic/cheap LCD does not store the state of its pixels anywhere. It electrically refreshes them as the signal comes in, much like a CRT. The pixels are blocking light instead of emitting it, but they will still fade out if left unrefreshed for long. So, the simple answer is, you can't get direct access to something when it doesn't even exist in the first place.