The Next Big Innovation in Microprocessors: Anant Agarwal (Part 7)

SM: This is a radical redesign, and it seems it should be advantageous in other areas as well, right? AA: True. The other beauty of the mesh is that not only does it solve the performance problem, it also really addresses the power problem. A bus is a big centralized structure, and any big centralized structure will have to have high power. Big wires take a lot more energy than small wires. In mesh architecture, since each switch talks to a neighboring switch, the wires are shorter and the architecture is fully distributed making it much more energy efficient.

SM: The energy issue is tackled at the interconnect level? AA: That is a big part of it. For example, in bus based multicore setups, it is not unusual to see 30% of the power gets consumed in the buses. You also have big centralized structures like caches. By moving away from big structures, you get further power efficiency that comes from the tiled approach. Rather than having any single big structure, you make various small structures.

SM: What is the second major innovation? AA: The second part is the full featured processor cores. The idea is, you want full featured processor cores to be able to compile off the shelf applications on any core. The real challenge is how to balance the core size. How do you build beefy cores and yet have lots of cores on the chip. Through the work we have done we have a good idea of what the right size of a core needs to be. Our cores are full featured general purpose cores, they can run off the shelf C programs, an operating system, and they have L1 and L2 caches. The benefit is that you can run standard operating systems, and give people a familiar environment which means they can compile and run their existing software.

SM: In the kinds of applications you are targeting, you do not really need to run Vista, right? AA: There again, it can be done if needed.

SM: Which operating systems are you targeting? AA: We are in the embedded space, and that is where Linux is the major force. This chip can run other operating systems, so if you see a poll from our customers you will notice we could handle other operating systems but there is simply no demand for it right now.

[To Be Continued]

[Part 6]
[Part 5]
[Part 4]
[Part 3]
[Part 2]
[Part 1]

This segment is part 7 in the series : The Next Big Innovation in Microprocessors: Anant Agarwal
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