新换手机SAMSUNG GT-I9500，正在到处爬文中，翻阅出这样一篇技术资料。保存备用。
转自机锋，后半部分的内容更加重要
I’m going to write this as an guide/information page so we stop as soon as possible the stupid discussions about how 8 cores are useless.
我写这篇文章作为guide/information page ，我们也尽快停止关于8核心处理器多没用的愚蠢讨论吧
What’s it all about?
这是关于什么的？
The Exynos Octa or Exynos 5410 is a big.LITTLE design engineered by ARM and is the first consumer implementation of this technology.
Exynos Octa 或者说 Exynos 5410 是ARM设计的big.LITTLE 架构处理器，并且是这种技术的第一个消费级产品。
Samsung was their lead partner in terms of bringing this to market first. Reneseas is the other current chip designer who has publicly announced a big.LITTLE design.
三星是ARM推广这种处理器的主要合作厂家， Reneseas 也有类似的big.LITTLE架构芯片。
Misconception #1: Samsung didn’t design this, ARM did. This is not some stupid marketing gimmick.
说明1：big.LITTLE架构不是三星设计的，是ARM设计的，这不是什么愚蠢的商业噱头。
The point of the design is to meld the advantages of the A7 processor architectures, with its extreme power efficiency, with the A15 architecture, with extreme performance at a cost of power consumption.
这种设计的终点在于融合A7处理器的低功耗和A15芯片的高性能的优点。
The A7 cores are slightly slower than an A9 equivalent, but using much less power. The A15 cores are in another ballpark in terms of performance but their power consumption is also extreme on this current manufacturing generation.
A7处理器比起A9来说性能上稍有欠缺，但是却省了不少电。A15核心性能NB但是在现在的制程下，却是个耗电大户。
The effective goal is to achieve the best of both worlds. Qualcomm on the other does this by using their own architecture which is similar in some design aspects to the A15 architecture,
最终目的是联合两种芯片的有点，高通的解决方案是使用他们自己的类似A15的结构。
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Currently, the official word seems to be that the A7 cluster is configured to run from 200 to 1200MHz, and the A15 cluster from 200 to 1600MHz.
现在，官方辞令好像是A7频率为200–1200MHz，A15 200–1600Mhz
There are several use-cases of how the design can be used, and it is purely limited by software, as the hardware configuration is completely flexible.
下面有几个应用案例来表明这种架构是怎么工作的，并且，这些应用模式完全由软件决定，硬件完全没有限制。
In-Kernel Switcher (IKS)
内核切换
This is what most of us will see this in our consumer products this year; Effectively, you only have a virtual quad-core processor.
这是今年大多数人将在我们的消费品中看到的：我们的八核心处理器工作起来就类似一个虚拟四核处理器
The A15 cores are paired up with the A7 core clusters. Each A15 has a corresponding A7 “partner”. Hardware wise, this pair-up has no physical representation as provided by an actual die-shot of the Exynos Octa.
A15核心和A7核心一一配对。每个A15核心都有一个对应的A7伙伴， 但在硬件层面， Exynos Octa 并没有在硬件层面绑定这种结构
The IKS does the same thing as a CPU governor. But instead of switching CPU frequency depending on the load, it will switch between CPUs.
内核切换程序实际上做为CPU管理者，并不是简单的根据功耗频繁切换CPU。
Effecively, you are jumping from one performance/power curve to another: And that’s it. Nothing more, nothing less.
实际上，使用过程中，用户只是在两条功耗/性能曲线中跳跃，就是这样。
The actual implementation is a very simple driver on the side of the kernel which measures load and acts much like a CPU governor.
实际的内核切换进程是非常简单的：充当CPU管理者测量功耗和性能。
The above is a demonstration; you can see how at most times the A7 cores are used for video playback, simple tasks, and miscellaneous computations.
上面的说明中，你可以明白多数时间中A7可以进行视频回放等简单的工作，和一些五花八门的计算工作。
The A15 cores will kick in when there is more demanding load being processed, and then quickly drop out again to the A7 cores when it’s not doing much anymore.
当某一时刻需要更多性能时，A15核心就会介入。如果不再需要高性能时，又会立刻切换到A7芯片。
Misconception #2: You DON’T need to have all 8 cores online, actually, only maximum 4 cores will ever be online at the same time.
说明2：你不需要8个核心同时工作，最多4个核心同时工作。
Misconception #3: If the workload is thread-light, just as we did hot-plugging on previous CPUs, big.LITTLE pairs will simply remain offline under such light loads. There is no wasted power with power-gating.
说明3：如果负载不大，那么就切换到前期工作的CPU上，在小负荷中，不会调用新的big.LITTLE伴生对参与计算，不会造成功耗增加。
Misconception #4: As mentioned, each pair can switch independently of other pairs. It’s not he whole cluster who switches between A15 and A7 cores. You can have only a single A15 online, together with two A7’s, while the fourth pair is completely offline.
说明4：特别说一下，每个A7+A15伴生对可以独立切换，并不是要么4个A7工作要么4个A15工作。你可以只有1个A15+2个A7核心工作，同时，第四对伴生对不参加工作。（负载大概在8000DMIPS以上的时候,A7所有核心都切出工作，而在约5000DMIPS以下的时候，A15是不参与计算的。5000–8000DMIPS阶段，1个A15核心+2~3个A7核心共同负担计算。）（1GHZ运行时，a8核心2000DMIPS ，a9为2200DMIPS。a7和a9差不多）
Misconception #5: The two clusters have their own frequency planes. This means A15 cores all run on one frequency while the A7 cores can be running on another. However, inside of the frequency planes, all cores run at the same frequency, meaning there is only one frequency for all cores of a type at a time.
说明5：4个A7核心和4个A15核心有他们自己的工作频率，这意味着可以A15核心工作在一个频率上，而同时A7核心工作在另一个频率上。但是，相同种类核心只能运作在同一频率下。