One of the reasons E Ink displays consume less power than LCD screens is because they only draw power when the image on the screen changes. You can leave a Kindle or NOOK reader open to a page in a book for weeks without any noticeable power drain. Try doing that with a notebook or tablet and see how far you get.
But chip maker Intel is pushing a new technology it calls Panel Self Refresh which could bring some of the same power-saving features to full color computer and tablet displays.
Basically a combination of magic on the chip, display, and software, would allow screens to save power by only refreshing the image on the screen when it changes.
If you’re watching a video or playing a game you want the screen to refresh 30 to 60 times per second so that the moving graphics look smooth. But if you’re reading an eBook or browsing the web, odds are you’re staring at a static image on the screen for a few seconds at a time. So why does your display constantly refresh the image?
Intel says its Panel Self Refresh technology could allow for mobile devices with longer battery life by working more like E Ink displays… but with color.
Of course, notebooks, tablets, and other mobile computers have plenty of other components that use more electricity than those in eReaders, including faster processors, higher quality screens, sensors, and cameras. So you probably won’t be measuring notebook battery life in months anytime soon.
This is interesting, but isn’t conceptually like e-Ink at all. With e-Ink, the display refresh rate equals the rate at which the image changes. No change to image? No refresh on the display at all. Intel’s proposed tech still keeps updating the display at the display’s native refresh rate but uses a frame buffer on the display rather than pushing a new image off of the graphics processor for each frame when the image is static. That lets the GP enter a lower idle state, and is the major source of power savings happening here. There’s also some savings by notifiying the display that nothing is happening and letting it drop to an interlaced refresh rather than a progressive refresh, although that is certainly less clear in the slides and other info I’ve just looked up.
So much of the way displays work is still guided by thinking rooted in the era of CRTs. You *had* to update those at some minimum refresh rate, otherwise the phosphors stop emitting photons. LCD panels are a different beast. There’s really no reason to refresh the screen at all when the image hasn’t changed, which leaves me puzzled about sticking with the native refresh rate and requiring a framebuffer.
One step at a time perhaps?
Yes, this is more or less just a efficiency enhancement for the computer itself but there are other advances they’ll be pushing for the screens themselves.
For example, they’re soon be able to start using ambient light to help boost back lighting to greatly reduce how much energy that consumers. Along with more efficient screens.
Though some of that is being offset by the higher resolutions coming out that unfortunately increase the need for back lighting and higher load on the system, but by next year we should see enough of an overall improvement to finally see some real improvement in average run times.
Using ambient light already happens if one have a transflective screen. Btw, i suspect that for this to take off it needs to make its way onto ARM SoCs.
The difference is the upcoming screens won’t compromise on screen quality.
Like how Pixel Qi screens lack color when in reflective mode.
They’ll just look like normal screens but with the use of ambient light to boost the back lighting, which also means it naturally scales up as the ambient light intensity increases and thus makes it easier to view in even direct sun light.
Also they’re working on transparent glass, which means even capacitive touch screens will no longer have glare… at least noticeable and eliminates the need for a anti-reflective layer.
While it’s not important that these screens make their way onto ARM based systems but rather that a lot of them get adopted for at least the popular size devices as then they’ll become cheaper to make and in turn more likely to be used.
Sounds interesting, tho one wonder why it is not already in widespread use.
Pretty much the same reason a lot of power saving technology isn’t widely used yet.
One… Aside from mobile devices there hasn’t really been a need and requires a rethinking on the way to do things. So there hasn’t been a real push for it up till now.
Two… The technology took awhile to perfect as switching between idle and active can add latency and cause sluggish responsiveness.
Mind it took years for screen responsiveness to become good enough for things like gaming, but now we’re at the point where there is now a push for greater power efficiency in a wider range of products and the technology is mature enough to provide the bonus without inducing any hit on performance.
Though, like Mr. T indicated, this isn’t really comparable to e-ink and it depends on what you’re doing but potentially it can add up to an hour to the run time of a given laptop.
However, this isn’t the only power efficiency boosting technology they’re bringing in with the next gen systems and all told we may see up to a 50% reduction in power consumption than what’s available now.
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