editor's blog
Subscribe Now

Big and Little Core Combos

A long while back ARM introduced their big.LITTLE concept. (So cute how they put the big in little letters and the little in big letters! Did you notice that?) The general concept is to have one beefy processor for heavy lifting and one small one for light duty; by powering them up and down, you can save energy by assigning the right core to the right task.

But at last week’s Multicore DevCon, processor guru Linley Gwennap showed, among other things, various ways in which companies are implementing this concept. Although, of course, ARM figures in all of them.

  • Nvidia includes an A15 CompanionCore (their original whitepaper shows an A9). Yeah, an A15 is the “little.” The point is that, unlike the other A15s on the chip, this one is optimized on the low-power end of the process, so it has less performance but consumes less power.
  • Samsung is going more the way ARM suggested: pairing an A15 with an A7. The A7 is 3.3 times more power efficient in MIPS/W; twice as efficient in MIPS/m2. But the A15 is 3 times faster.
  • Samsung’s Octa is more complicated. It has 4 A15s and 4 A7s, all software compatible so that any software can run on any of them. Problem is, Android is running on it, and, for now, Android doesn’t like mixtures of core types: it want’s homogeneous (apparently a future rev won’t). So you can’t run both sets of four cores at the same time. If you want performance, then you run the four A15s and the A7s are powered off; if you want to run with lower power, then you shut the A15s down and power up the A7s and run them. That’s where the software compatibility is critical.
  • Qualcomm fakes it, you might say. They have an A15, and they just clock it way down to save power. This is almost as effective as using an A7.

Clearly lots of ways to skin that cat…

Leave a Reply

featured blogs
Jun 22, 2021
Have you ever been in a situation where the run has started and you realize that you needed to add two more workers, or drop a couple of them? In such cases, you wait for the run to complete, make... [[ Click on the title to access the full blog on the Cadence Community site...
Jun 21, 2021
By James Paris Last Saturday was my son's birthday and we had many things to… The post Time is money'¦so why waste it on bad data? appeared first on Design with Calibre....
Jun 17, 2021
Learn how cloud-based SoC design and functional verification systems such as ZeBu Cloud accelerate networking SoC readiness across both hardware & software. The post The Quest for the Most Advanced Networking SoC: Achieving Breakthrough Verification Efficiency with Clou...
Jun 17, 2021
In today’s blog episode, we would like to introduce our newest White Paper: “System and Component qualifications of VPX solutions, Create a novel, low-cost, easy to build, high reliability test platform for VPX modules“. Over the past year, Samtec has worked...

featured video

Reduce Analog and Mixed-Signal Design Risk with a Unified Design and Simulation Solution

Sponsored by Cadence Design Systems

Learn how you can reduce your cost and risk with the Virtuoso and Spectre unified analog and mixed-signal design and simulation solution, offering accuracy, capacity, and high performance.

Click here for more information about Spectre FX Simulator

featured paper

Carmakers charge ahead with electric vehicle powertrain integration

Sponsored by Texas Instruments

When we advance EV powertrain architectures, carmakers can cut system-design cost in half while maximizing power density, increasing efficiency, improving reliability and making EVs more affordable for more people.

Click here to read more

featured chalk talk

The Wireless Member of the DARWIN Family

Sponsored by Mouser Electronics and Maxim Integrated

MCUs continue to evolve based on increasing demands from designers. We expect our microcontrollers to do more than ever - better security, more performance, lower power consumption - and we want it all for less money, of course. In this episode of Chalk Talk, Amelia Dalton chats with Kris Ardis from Maxim Integrated about the new DARWIN line of low-power MCUs.

Click here for more information about Maxim Integrated MAX32665-MAX32668 UB Class Microcontroller