I'd really question the theory that #cores will grow exponentially.
Be interesting to see some evidence that's likely to happen.
Be interesting to see some evidence that's likely to happen.
If you really think Larrabee is only a GPU, think again. Each core is a full 64-bit x86 that can quite happily run anything that´s running on my Core 2 Duo.
If you believe it will continue, and that clock speeds won't increase, then you get exponentially increasing #'s of cores (or some other use of silicon estate).
An alternative scenario is that there will be no mainstream demand for more computing power, and only niche markets will buy them. The mainstream will favour cheap, less powerful CPU's. The rise of eeePC and clones is suggestive of this scenario.
Only if you believe the wiring connecting the cores wouldn't explode with the number of cores.
A single bus works fine for moving data to/from one of many memory locations. Another method of using just one bus is TCP-IP packet-style communication. Of course, there's limited bandwidth, so you want most of your computation done within a processor, not between them.
For many problems, bisection bandwidth is a key constraint.
As long as you clear ~100 cores, I think you're done.
Why do you think so? The 2007 book "Future Directions in Processor Design" says (p483, Ch21):
http://www.springerlink.com/content/xp811205j8523537/
If we think of the technology development as predicted in the ITRS roadmap [208], it is clear that more and more processors will be crammed onto a single chip. The prediction for the roadmap is that we will see hundreds or even thousands of precessors integrated within the next ten ... fifteen years, e.g., 424 precessing elements per chip in 2017. The trend can be confirmed by looking at some ambitious high-end projects in multi-core and multi-processor development. For example, Rapport Inc. is shipping a chip with 256 processing elements on board and is developing a 1,024-core processor, however these are only 8-bit elements [281].
...
My bet is that we will see more specialized processors for different specific tasks. The "one size fits all" simply cannot provide enough cost and power efficient enough solutions for the embedded sector. Thus, we will see various special-purpose off-the-shelf cores emerging.
It isn't an argument about the technology, rather about what humans will be able to manage.