LG G2 comes with Graphic RAM, but what is it?

by: Gary SimsAugust 8, 2013

LG G2 DisplayLG has launched its new flag ship smartphone the G2. Along with its Qualcomm Snapdragon 800 processor, full HD 5.2-inch IPS LCD display and interestingly positioned volume buttons – the LG G2 also comes with something called Graphic RAM.

According to LG, Graphic RAM (GRAM) reduces the display’s energy use by up to 26 percent on a still frame and increases overall usage time on the device by approximately 10 percent. Sounds good, but what is it?

Graphic RAM is the name LG is using for a technology called Panel Self Refresh. It has been around for a couple of years but this is the first time it has been used in a mobile phone. When anything is displayed on a smartphone or tablet, even the page of an eBook with nothing moving, the GPU is sending the frame image to the display panel 60 times per second. The same image over and over again. When something changes the new screen is rendered by the GPU and the process starts again. Of course for games or videos the rate at which the GPU and display panel can show the frame is essential. But when reading an eBook or surfing the web there are large amounts of time (from the GPU’s perspective) when everything is static and nothing changes.

GRAM adds a memory cache to the display panel which is used to display the same frame over and over again without any communications with the GPU. When the CPU and GPU see that nothing is changing a command is sent to the display panel telling it to take a screen capture of the current frame and to keep displaying it until told otherwise. In the meantime large bits of the System-on-a-Chip (Soc) circuity including parts of the GPU can be shutdown and so saving valuable energy.

Of course this all happens in the blink of an eye (well less in fact) and the user doesn’t see any difference at all, but in the background different parts of the SoC are shutting down and firing up, much in the same way that idle cores on dual-core or quad-core CPUs are shutdown and started as needed.

LG reckons that this technology reduces the display’s energy consumption by 26%. That is significant and also gives us a glimpse into how much power is used by SoC when refreshing the display, even a static one. The display panel itself will still consume power as it is still refreshed 60 times per second but the data is now coming from within the display panel circuitry. Overall there is a 10% power saving which is also significant, but it also shows us how active the displays are on our Android devices!

  • Ram

    In short, gimmick

    • ConCal

      Not a gimmick. Samsung’s hand waving gestures is a gimmick. This is somewhat useful. Even a 5% battery savings overall (when the user does nothing different at all) is great!

      • lil bit

        But it’s still amazing how how many people rather wave their hands or want to talk to the phone in the pocket. Some even praises customizable color and boot animation as “finally, this was what my life was always missing, I’m complete now”.

        Crossbreed a Moto X with an S4 and you get a phone you can wave at while in your pocket and none can ever guess the name of itsback cover color.

        • Sean Bunquin

          Actually If google now can be commanded to do things offline (such as set an alarm, note, short text messages, setting calendar events, calling someone) then the utility of touchless control can be enhanced. though it will take some getting used to

        • BB BB

          Samsung is probably already working hard making their own touchless commands which we will see featured on the Note 3. Maybe the stylus will eject itself when you visit Page 3.

      • Jaun Lombard

        I really dont see why Samsung’s Air-gestures are gimmicks…from keypad to touch screen to touch-less interface…I see it as the future… Samsung is just prepping it!

        • Grman Rodriguez

          The thing is why would you wave your hand at something that is on your other hand? Maybe a TV or a PC that are considerably far away, but a phone is like 20 cm away from your head and already in your hands, why wouldn’t I touch it?

          • TheScientists

            Just one example: Cooking in the kitchen, phone laying on the counter, hands covered in food.

          • Grman Rodriguez

            I know, it’s not useless just not “the future of handling your phone” because it doesn’t transform the way you interact with your phone just helps in very situational occasions

        • lil bit

          It’s like being in bed with a model and not touching her because fapping is the future.

          • YoungHermit

            Haha! Nice one, even though I love the air gestures

        • YoungHermit

          Though I agree with you, they sort of went the wrong way. Let’s say your phone is in your pocket, your hands are dirty and you get a call, you have to pick it up. It’ll get dirty, so what’s the point of using the air gesture? They should have put an OIS instead of those sensors, honestly

    • PacoBell

      I see what you did there…I think?

  • ConCal

    I love all these new new features/technology. It seems like everything a new flagship is announced were getting cool new features most of us never thought of.

  • Mohd Danial

    Cool tech.

  • Mohd Danial

    Cool tech.

  • Lil bit

    Rest assured, these 10 percent savings are best case scenario, real life savings will vary wildly from one user to another, for lots of us the saving could be close to zero.

    By the way, sending stuff to the display is not the job of the gpu, the display controller takes case of that, the gpu should be able to enter a lower power state regardless of the presence of gram. Suspending the display controller and the bus should of course help still. Nevertheless, the 26 and 10 percent are numbers from marketing department and not from engineers or devs, take it with the usual big dose of salt, technical facts and marketing facts are two very different things.

    • Cao Meo

      Well most people do a lot of reading, watching photos or browse the web so this tech is great

      • lil bit

        Have you tried it already?

        I didn’t think so.

        • AndroidBrian

          Have you? I didn’t thinks so. Some people are optimist and some are…. U. From what we read in the article it does seem like it will save a some battery. People do read & browse the web, there for GRAM will extend there battery life.

  • jayray78

    If the pixels aren’t getting refreshed wouldn’t that leave them more susceptible to burn in?

    • Hdom

      I believe they are getting refreshed at the same rate, just by a different device, which uses less power than the GPU.

    • Seth Forbus

      Burn in hasn’t been an issue since early plasmas. Modern displays can leave things sitting on them for hours. The difference, is if its refreshing from the graphic ram, it uses way less power than the GPU actually rendering it. The GPU takes a lot of power in any device to actively render something.

    • stucrmnx120fshwf

      Aren’t the pixels being refreshed 60 times a second from the graphics RAM, just that we don’t see it, probably progressive scan though, so the screen time out, would help to eliminate spot burns, the point is it doesn’t have to go through the processor all over again, at least that’s what I think they’re saying. I was hoping, it was some kind of low power GDDR5 ie. LPGDDR5, with 14 nm, 64 bit, maybe UD (4k,) coming next year we could use it, the less bottle necks, pipeline clogs, the better.

  • chaoslimits

    Isn’t the actual display (powering pixels) the largest battery suck? I don’t get how you get 26% less power usage when the pixels are still on?
    I guess we’ll know when the reviews are released (like for the Moto X’s mediocre battery life).

    • stucrmnx120fshwf

      Think your right, number of lumens is highly important, a 1 pixel, one color torch, would use more energy than an ultra definition 6″ screen, light is energy after all, stored electrical energy, converted into optical energy, if you look in settings battery, display features big time.

  • Tamadrummer94

    Hm, sounds like a good step forward, but doesn’t IGZO tech offer the same advantages, but better? Unless I’m remembering incorrectly, I think the power savings with IGZO are way more dramatic.

  • Brian Hyun Hurh

    Man, I’m a guy who always want the best thing out there. I bought the gs4 for that reason but the g2 looks amazing.

    • Rhino”

      G2 is what the S4 should have been …instead the S4 was a refresh on the S3.
      i think for me Lg ticked a lot of boxes with the G2…i am still going to see how the note 3 turns out before i make my decision but yes note3, maybe the Sony z ultra but G2 is definitely top of list so far,.. at least it impressed me.. :)

    • BB BB

      I think you made the right choice with the S4. I would be tempted by the G2 but I like what Samsung does with Android better than LG. Samsung will probably release an S800 S4 and refresh it soon to keep it neck to neck with the G2 not that it isn’t already. The initial G2 benchmarks scores weren’t much better than the S4 which is a bit puzzling how the S800 on the G2 could score so badly.

  • john

    Panel self fresh is really nothing new, especially in these new eDP 1.3 and above panels. It doesn’t do much for the actual performance, but can help save quite a bit of power. I think LG should get some credit as the most of high resolution eDP panels-maybe all of them- are made by LG, eg) iPad retina, MBPr, other cute high res devices.


    So…….a buffer? That’s not new.

  • Seth Forbus

    About time a phone had Graphic Ram. I can’t wait until the DDR5 G-Ram we see in desktop GPU’s makes it to phones. The only thing I’m confused about is the Tegra 4 by Nvidia. I thought it had G-Ram.

  • Luka Mlinar

    Like a car start-stop system. Me gusta!

  • Eddy

    For users interested primarily in specs and hardware, the G2 has plenty to offer. But for most smartphone shoppers, this phone is going to have a tough time standing out in the crowded menu of enticing Android options.