ARM A53/A57/T760 investigated - Samsung Galaxy Note 4 Exynos Review
by Andrei Frumusanu & Ryan Smith on February 10, 2015 7:30 AM ESTConclusion
Samsung's System LSI business had a rough two years as their decision to go with ARM's big.LITTLE SoC architecture cost them a lot of market share, thanks in part to immature software and implementation issues. Usually in the past Samsung's own Exynos SoCs were regarded as the more performant variant given the choice of Qualcomm's Scorpion CPU based solutions. This changed as the Exynos 5410 came out with a malfunctioning CCI, crippling the chip to the most battery inefficient operating mode of big.LITTLE.
Qualcomm's Snapdragon 800 capitalized on the new 28nm HPM manufacturing process, along with the advantage of being able to offer an integrated modem solution, and has dominated the market ever since. It's only now that Samsung is able to recover as the new 20nm manufacturing process allowed them to catch up and start to offer their own Exynos SoC in more variants of its products, a trend that I expect to continue in Samsung's future lineup.
The Note 4 with the Exynos 5433 is the first of a new generation, taking advantage of ARM's new ARMv8 cores. On the CPU side, there's no contest. The A53 and A57 architectures don't hold back in terms of performance, and routinely outperform the Snapdragon 805 by a considerable amount. This gap could even widen as the ecosystem adopts ARMv8 native applications and if Samsung decides to update the phone's software to an AArch64 stack. I still think the A57 is a tad too power hungry in this device, but as long as thermal management is able keep the phone's temperatures in reign, which it seems that it does, there's no real disadvantage to running them at such high clocks. The question is whether efficiency is where it should be. ARM promises that we'll be seeing much improved numbers in the future as licensees get more experience with the IP, something which we're looking forward to test.
On the GPU side, things are not as clear. The Mali T760 made a lot of advancements towards trying to catch up with the Adreno 420 but stopped just short of achieving that, leaving the Qualcomm chip a very small advantage. I still find it surprising that the Mali T760 is able to keep up at all while having only half the available memory bandwidth; things will get interesting once LPDDR4 devices come in the next few months to equalize things again between competing SoCs. Also ARM surprised us with quite a boost of GPU driver efficiency, something I didn't expect and which may have real-world performance implications that we might not see in our synthetic benchmarks.
It's the battery life aspect that I think it's most disappointing to me. It's a pity that Samsung didn't go through more effort to optimize the software stack in this regard. When you are able to take advantage of vertical integration and posses multi-billion dollar semiconductor manufacturing plants with what seem to be talented SoC design teams, it's critical to not skimp out on software. I might be a bit harsh here given that the battery disadvantage was just 12% in our web-browsing test and might be less in real-world usage, and the GPU battery efficiency seems neck-and-neck. Still, it's the wasted potential from a purely technical perspective that is disheartening.
This is definitely a wake-up call to ARM and their partners as well. If the software situation of big.LITTLE isn't improved soon I'm fearing that ship will have sailed away, as both Samsung and Qualcomm are working on their custom ARMv8 cores.
So the question is, is it still worth to try and get an Exynos variant over the Snapdragon one? I definitely think so. In everyday usage the Exynos variant is faster. The small battery disadvantage is more than outweighed by the increased performance of the new ARM cores.
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tipoo - Tuesday, February 10, 2015 - link
Agreed, it was a little shocking to see that even the Cortex A57 is stomped on by the A8/Cyclone R2. And that with two cores and sane clock speeds.I would say this is what everyone else would be doing, ideally, but the cost here is die size. Instead they shoot for smaller higher clocked designs to save some die size and cost, since other companies aren't willing to pay as much for the SoC in the BoM as Apple is.
ruggia - Tuesday, February 10, 2015 - link
to be fair, the basic minimum performance Cyclone R2 have had to achieve was beat A57, since that was the reference design available from ARM for everyone. So I don't think it's that surprising.tipoo - Tuesday, February 10, 2015 - link
On the other hand, them and Nvidia alone have parts better than the A57 per-core out, and even from those two the 64 bit Denver K1 is too high in power draw and chokes on some tasks due to its code morphing engine bottlenecking the process.So it is still remarkable, to me, how early and how long Apples lead has lasted.
Kidster3001 - Friday, February 27, 2015 - link
Why do we need octa cores in phones/tablets? Marketing says we do, plain and simple. It's bragging rights. No real benefit but it sounds cool. Apple is doing it wider and smarter.DarkLeviathan - Saturday, December 19, 2015 - link
But unfortunately people are getting dumb-er and stupid-er (XD). Falling into marketing ploys. I feel like Apple is the one who is not marketing crazy now. Its all numbers with the Android people :/ Apple cares about user experience more than any other companies and they spend a lot more money on it.xdrol - Tuesday, February 10, 2015 - link
Please go compare it to nVidia Denver cores.tipoo - Tuesday, February 10, 2015 - link
I have. It wins some benchmarks, but is less consistent in the real world because it's a code morphing design that can get choked up by unpredictable code. It's also more power hungry, though that's partly the fab.lilo777 - Tuesday, February 10, 2015 - link
bigstrudel, you are either Apple fanboy or a troll. For your own sake I hope it's the former and you understand that what you posted is pure nonsense. The only tests where iPhone dominates Samsung phones are specint and basemark tests. But the reason for that is not what you probably think it is. Specint benchmarks use only one core. Sure, A8 core is faster but then iPhone has just two of them. The total power of four cores is higher than that of two A8s. And it's not like the two A8 cores consume twice less power than four Samsung cores. A8 is a very BIG core. Each A8 core uses more power than a single Samsung core. And basemark scores... Those depend on screen resolution and iPhone has a very low resolution compared to Note 4. In short, both approaches (two large cores or big.LITTLE architecture) have pros and cons. There is no magic here. It is not clear to me why would you say that A8 "stands light years ahead" when the phone based on this SOC (iPhone 6) lags high end Android phones in synthetic benchmarks like Geekbench.DarkLeviathan - Saturday, December 19, 2015 - link
1. The CPU and resolution has almost nothing in which you can compare with2. If you do a little research and stop drinking that Samsung marketing soup, you would realize that not all the Samsung cores are not the same. They vary in power...
PC Perv - Tuesday, February 10, 2015 - link
Apple A series is already eclipsed by Exynos 5433 as seen by sub-test scores in Geekbench. (how does Geekbench calculate aggregate score? I have no idea) A8 will also be crushed and humiliated by soon-to-arrive Exynos 7420.Dual-core is the best configuration? My ass. That is why they added another core in the new iPad. Oh, if you look at the die shot there is a space for a 4th core there, too.