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Samsung's Exynos 5 Octa to hit OEMs this summer

Samsung's Exynos 5 Octa to hit OEMs this summer

Samsung's Exynos 5 Octa, the eight-core processor at the heart of the Galaxy S4, will hit the open market in summer, the company has confirmed.

Samsung has confirmed plans to bring its Exynos 5 Octa eight-core processor to third-party companies by the end of the second quarter, heralding a potential boom in high-performance, high-resolution mobile devices and more.

Originally announced back in January, the Exynos 5 Octa is the chip behind the freshly-announced Samsung Galaxy S4 - in some markets, at least. Based on a design principle put forward by Cambridge-based chip design giant ARM known as big.LITTLE, the processor pairs four high-performance Cortex-A15 processing cores - the same as found in other Exynos 5 parts - with four lower-power Cortex-A7 cores. The result is, by the numbers, an eight-core chip - but the idea is to have only one quartet of cores running at any given time.

The design is ARM's mean of addressing the two biggest demands in the mobile device world: increased processing power and increased battery life. As developers demand more horsepower from smartphones and tablets, the power required by the processor rises; but to get an appreciable increase in battery life, processors need to be designed to draw less power.

It's a puzzle that big.LITTLE addresses by running the phone on the four low-power cores during non-intensive tasks, such as web browsing, making calls, listening to music or playing back a video. Designed as low-leakage parts, the Cortex-A7 chips don't offer anywhere near the performance of ARM's latest Cortex-A15 design - but they also don't draw nearly as much power. When the phone or tablet switches into a high-demand situation, such as the launch of a game, the Cortex-A15 cores are powered up and all running tasks shunted across before the Cortex-A7 cores are powered down. When their grunt is no longer required, everything is shuffled back to the Cortex-A7 cores so the battery-draining Cortex-A15 cores can be put back to sleep.

It's far from the first such attempt to pair special low-power cores with more powerful parts in the name of energy efficiency: Nvidia's last-generation Tegra 3 and current-generation Tegra 4 pack a single-core processor designed to handling background tasks in the hope that the four main cores can spend much of their time powered down. Samsung's Exynos 5 Octa, however, will be the first to market with a full quad-core implementation of ARM's big.LITTLE.

Currently, the chip is exclusive to Samsung's Galaxy S4 smartphone, although rumours suggest the upcoming Galaxy Note 3 will also include the Exynos 5 Octa. As with previous Exynos chips, Samsung won't be keeping the device to itself but offering the part to other original equipment manufacturers (OEMs) as part of its chipmaking business.

Thus far, Samsung hasn't named any potential customers - but with the Exynos 5 Octa being the first sort-of-eight-core processor for the tablet and smartphone market, it's likely numerous manufacturers will be jumping on the bandwagon and adopting the design. That also means that, potentially as soon as by the end of the year, we're likely to see high-resolution, high-performance tablets powered by the chip, which is capable of driving display resolutions up to 2,560x1,600 (WXGA.) The chip is also likely to find favour with single-board computer manufacturers, who are likely to attempt to run all eight cores simultaneously for low-power high-throughput parallel processing tasks.

Sadly, all of this remains in the future - and if you want to play with the Exynos 5 Octa now, you're going to have to join the queue for a Galaxy S4.

11 Comments

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ya93sin 15th March 2013, 12:57 Quote
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.
schmidtbag 15th March 2013, 13:18 Quote
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.
Guinevere 15th March 2013, 15:04 Quote
Quote:
Originally Posted by schmidtbag
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.

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.
Gareth Halfacree 15th March 2013, 15:12 Quote
Quote:
Originally Posted by Guinevere
Quote:
Originally Posted by schmidtbag
Wouldn't using just 4 A15 cores and down-volting them be just as effective but a lot less complicated and less expensive?
I think you'll find it will be a lot more efficient to use a more optimised set of silicone.
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.
schmidtbag 15th March 2013, 15:16 Quote
Quote:
Originally Posted by Guinevere
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.

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.
rollo 15th March 2013, 16:17 Quote
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.
damien c 16th March 2013, 09:16 Quote
Quote:
Originally Posted by ya93sin
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.

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.
ya93sin 16th March 2013, 12:33 Quote
Quote:
Originally Posted by damien c
Quote:
Originally Posted by ya93sin
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.

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.

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.
ch424 16th March 2013, 13:53 Quote
Quote:
Originally Posted by schmidtbag
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.

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 3.8mm2 for A7 and 19mm2 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!
Gradius 17th March 2013, 03:53 Quote
2,650x1,600 (WXGA) ?!!?

Should be 2,560x1,600 (WXGA) !
Gareth Halfacree 17th March 2013, 11:22 Quote
Quote:
Originally Posted by Gradius
Should be 2,560x1,600 (WXGA) !
Typo - fixed, ta!
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