OnQ

How ARM architecture and Snapdragon processors are supporting the 64-bit future of mobile

2014년 8월 27일

Qualcomm products mentioned within this post are offered by Qualcomm Technologies, Inc. and/or its subsidiaries.

We recently teamed up with ARM Holdings and published a joint white paper exploring the advantages of the ARMv8-A instruction set and Qualcomm® Snapdragon™ processors. Altogether it came to 20 amazing pages, which you’re welcome to read, but if you’re just looking for a few talking points to liven up a party, the following summary will serve you well.

The whole reason we decided to gather this information into one place is because more than 95% of smartphones use the ARM instruction set architecture (ISA). ARM Holdings licenses both the CPUs using this ISA, and the ISA itself. Qualcomm Technologies, Inc. (QTI) licenses both for use in our Snapdragon processors. Here’s why that’s good:

The fact that so many phones use the same ISA is good for developers, and good for the people who use their apps. To get the best performance out of an application, most developers compile the code for the target platform, in this case ARM. That’s why most apps in Google Play target the current ARM instruction set, ARMv7-A. I wrote another article about the Snapdragon compiler if you’d like to learn more.

By compiling the code for their target platform, developers can be sure the user experience is exactly what they mean it to be.

The benefits include smoother gameplay and faster performance. The graph below shows the difference between native ARM apps, and those translated to x86. Jank is an official Android term for stutters on screen that interrupt smooth animations. The less jank, the smoother the experience: 

The next ISA, ARMv8-A, will add 64-bit support but will also be completely backward-compatible with the 32-bit ARMv7-A, so rest assured that users and developers alike will continue to reap the aforementioned benefits. The Cortex A57 and A53 CPUs are the first implementations of ARMv8-A, and they’ll deliver more performance than their A15 and A9 predecessors.

Snapdragon processors will use ARMv8-A CPUs and ISA. The upcoming Snapdragon 810 will use the ARM Cortex A57 and A53, while our next-generation 800 series processor will return to our custom CPUs.

The thing is, a mobile processor is so much more than a CPU. Snapdragon processors integrate the essential technologies to enable great mobile experiences; technologies like an LTE-Advanced modem, GPU, DSP, and a lot more. It’s a comprehensive package, an entire system right there on a chip. That way our processors can choose the right engine for the right job. We call it heterogeneous computing, and it is designed to make for better performance and more efficient battery usage. 

Snapdragon processors deploy a combination of our custom Qualcomm® Krait™ CPU architecture, alongside the standard ARM-designed CPUs. Today, the entry-level Cortex-A CPUs provide reliable, economical performance, while the Krait family of custom CPUs are designed to create a significant increase in performance efficiency in the high-end phones and tablets segments. The flexibility of being able to license the ARM instruction set or the Cortex CPUs allows us to build and offer a full and diverse product portfolio. Just like our all-in-one processors, we need the right tools for the right jobs. Snapdragon processors with integrated 64-bit ARM CPUs, when combined with the benefits of the ARM ecosystem and the many other custom technology blocks, will completely change the next generation of user experiences. For the best.

Here are some examples of scaling features and capabilities across the tiers of 64-bit Snapdragon processors:

Success in mobile computing, if nothing else, will depend on a thriving and productive ecosystem. We’ve seen that in the combination of integrated and customized processors. Through this relationship, ARM and Qualcomm will help to advance and evolve the ARM for Android ecosystem, including for the recently announced Android L (developer preview) release with ARMv8-A 64-bit support.