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News Samsung's Exynos 5 Octa to hit OEMs this summer

Discussion in 'Article Discussion' started by Gareth Halfacree, 15 Mar 2013.

  1. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

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  2. ya93sin

    ya93sin New Member

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    Still on a Samsung Galaxy SII which is brilliant, I think I will be upgrading to the SIV, it looks so packed when it comes to features.
    Watching the release live stream was pure agony though, like a theatre play.
     
  3. schmidtbag

    schmidtbag New Member

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    Wouldn't using just 4 A15 cores and down-volting them be just as effective but a lot less complicated and less expensive? I never got the impression that A15 was THAT much more power consuming than A7 - it still has a better performance-per-watt ratio than many Intel Atoms, possibly all Atoms.

    Also, I personally consider web browsing to be a relatively stressful task for ARM processors when you consider the amount of vector graphics involved. While 4 A7 cores can obviously handle that, I think 2 A15 cores would handle web browsing better.
     
  4. Guinevere

    Guinevere Mega Mom

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    I think you'll find it will be a lot more efficient to use a more optimised set of silicone. For the same reason the average i7 rig couldn't be undervolted and used in a digital watch. You use low performance - low power chips for low performance jobs.

    I'd be more concerned that it will result in laggy web experience etc and only kick in the extra ooomph when it really needs to. It all depends on how dynamic the switching is.
     
  5. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

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    This is the case: the energy efficiency gains come not from the fact that one set is a Cortex-A7 and one a Cortex-A15 design - that's pretty much inconsequential - but that one is designed for performance and one for power efficiency. If you build a processor to run at 1.5GHz, you can down-clock it to ~200MHz - but doing so doesn't save nearly as much power as you might think, because the voltage has to be kept above a certain level due to leakage. Build a chip specifically for low leakage, though, and that problem goes away - but you get a new one, which is that the chip will no longer clock to 1.5GHz. It's a trade-off, and one that having one of each - or four of each, in this case - solves.
     
  6. schmidtbag

    schmidtbag New Member

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    No I totally get that, but my point is I never heard of A15 being that much more power consuming than its predecessors. I feel like you can easily and safely under-volt and under-clock it to match A7 without weird performance issues like lagging. However, unless Samsung just has incompetent engineers, they must have already thought of and tested my idea. Also, I suppose I could be talking out of my ass anyways since I have never seen tests on A7. I've seen tests and used A8 and A9, but not A7. So A7 could be more power efficient than I expect.
     
  7. rollo

    rollo Well-Known Member

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    This is the first A15 chip thats been put into a phone and samsung have had to make a bigger battery for that phone to compensate for it.

    In the mobile space battery life is key.
     
  8. damien c

    damien c Mad FPS Gamer

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    Was waiting for the S4 to be released etc before I upgraded my phone and then after watching a few videos etc on it and finding most companies want a deposit for it, I have decided not to bother with it just yet.

    I have decided to go for a Galaxy Note 2 instead.

    Whilst the S4 is better, I just don't see why a phone need's a 8 core chip and seems pointless and a waste of money to me.
     
  9. ya93sin

    ya93sin New Member

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    Perhaps, I was not drawn to the processor but really to the larger screen, the better resolution, those kinds of things. I'm sure it will be quite expensive though.
     
  10. ch424

    ch424 Design Warrior

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    A7 is *really* efficient.

    A7 has a short pipeline, in order execution and quite narrow instruction issue. A15 is out of order, has a much deeper pipeline and quite complex out of order execution. This means that A7 is physically much smaller, so uses much less static power and much less dynamic power for an easy workload. However, because of its shorter pipeline you can't clock it as high. A15 will give you far higher performance when it's running at the same speed, but it'll use even more power. Samsung have said their implementation gives 3.8mm{param} for A7 and 19mm{param} for A15. That's a huge difference! Power gating the A15 when it's idle makes all that power consumption go away.

    Also, I do feel like you're talking out of your arse :p All CPU architectures get diminishing returns for increasing performance. I recently saw a comparison of an i7 and a Tegra 3. The i7 was 8x as fast in single threaded tests, but used 25x as much power. I'd be surprised if you could find a counter-example!
     
  11. Gradius

    Gradius IT Consultant

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    2,650x1,600 (WXGA) ?!!?

    Should be 2,560x1,600 (WXGA) !
     
  12. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

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    Typo - fixed, ta!
     

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