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
Sep 21, 2021
Placing component leads accurately as per the datasheet is an important task while creating a package footprint symbol. As the pin pitch goes down, the size and location of the component lead play a... [[ Click on the title to access the full blog on the Cadence Community si...
Sep 21, 2021
Learn how our high-performance FPGA prototyping tools enable RTL debug for chip validation teams, eliminating simulation/emulation during hardware debugging. The post High Debug Productivity Is the FPGA Prototyping Game Changer: Part 1 appeared first on From Silicon To Softw...
Sep 18, 2021
Projects with a steampunk look-and-feel incorporate retro-futuristic technology and aesthetics inspired by 19th-century industrial steam-powered machinery....
Aug 5, 2021
Megh Computing's Video Analytics Solution (VAS) portfolio implements a flexible and scalable video analytics pipeline consisting of the following elements: Video Ingestion Video Transformation Object Detection and Inference Video Analytics Visualization   Because Megh's ...

featured video

Product Update: Complete DesignWare 400G/800G Ethernet IP

Sponsored by Synopsys

In this video product experts describe how designers can maximize the performance of their high-performance computing, AI and networking SoCs with Synopsys' complete DesignWare Ethernet 400G/800G IP solution, including MAC, PCS and PHY.

Click here for more information

featured paper

Designing device power-supply ICs in an application-specific automated test equipment system

Sponsored by Maxim Integrated (now part of Analog Devices)

This application note provides guidelines for selecting the device power-supply (DPS) IC in an automated test equipment (ATE) system. These considerations will help you select the right DPS IC for your specific ATE system. It also explains the best system level architecture to tackle the output current and thermal requirements of the ATE system.

Click to read more

featured chalk talk

Automotive Infotainment

Sponsored by Mouser Electronics and KEMET

In today’s fast-moving automotive electronics design environment, passive components are often one of the last things engineers consider. But, choosing the right passives is now more important than ever, and there is an exciting and sometimes bewildering range of options to choose from. In this episode of Chalk Talk, Amelia Dalton chats with Peter Blais from KEMET about choosing the right passives and the right power distribution for your next automotive design.

Click here for more information about KEMET Electronics Low Voltage DC Auto Infotainment Solutions