[Arm-netbook] ARM big.LITTLE Processing

[Alain Williams]

Basically on one chip you have a Cortex-A15 MPCore and a Cortex-A7 core.
>From the programming viewpoint these look the same (same registers, instruction
set, ...) but the A15 is powerful but eats energy, the A7 is slow but uses
little energy. If the OS is running on the A7 and needs more power it migrates
itself to the A15 in some 20 microseconds and runs, but faster. When the work is
done it migrates itself back to the A7.

So: run in the core that is appropriate to the work load & save electricity.

You can also run both A15 & A7 cores at the same time, the A15 just gets more
work done.

The cores can each have several processors, the paper did not say how many.

See:

     http://www.arm.com/files/downloads/big_LITTLE_Final_Final.pdf

     http://www.arm.com/products/processors/technologies/bigLITTLEprocessing.php

This was talked about on el reg, who have completely misunderstood what this is about.

-- 
Alain Williams
Linux/GNU Consultant - Mail systems, Web sites, Networking, Programmer, IT Lecturer.
+44 (0) 787 668 0256  http://www.phcomp.co.uk/
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