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The Fight Against Dark Silicon
An anonymous reader writes "What do you do when chips get too hot to take advantage of all of those transistors that Moore's Law provides? You turn them off, and end up with a lot of dark silicon — transistors that lie unused because of power limitations. As detailed in MIT Technology Review, Researchers at UC San Diego are fighting dark silicon with a new kind of processor for mobile phones that employs a hundred or so specialized cores. They achieve 11x improvement in energy efficiency by doing so."
From the article, it seems like the processor usage would be transparent such that you don't need to explicitly target each processing element directly.
Language support for ubiquitous and provably threadsafe implicit parallelization -- done right -- is the answer to using generic dark silicon -- not building specialized silicon. See The Flow Programming Language, an embryonic project to do just that: http://www.flowlang.net/p/introduction.html
The CPU in a cell phone does not use much power so there is little to gain. Now if you can make more efficient radio transceivers - that would be something. Or the display, that would also significantly reduce power consumption. But adopting a new, unproven technology for minimal benefits.... That's not going to happen.
http://cseweb.ucsd.edu/users/swanson/papers/Asplos2010CCores.pdf
They call the specialized cores "c-cores" in the paper. I took a quick skim through it. C-cores seem like a bunch of FPGA's and they take stable apps and synthesize it down to FPGA cells with the use of the OS on the fly. The C-core to hardware chain has Verilog and Synopsis in it.
Cool tech, guess they could add gated clocking and all the other things taught in classroom to further turnoff these c-cores when needed.
cheers.
Why is it dark silicon they fight against? This represents the struggle of the black man to overcome racial prejudice and retake the word "nigger". The parallels are deep, man.
Exactly. Why do you think green olives are in glass jars and black olives are in tin cans? So the black olives can't look out. It's subliminal racism I tell you.
They can, they just don't want to. All they have to do is make it slightly thicker amd double the size of the battery. /without rebooting/.
Heck, I want to see a phone where the battery is the back cover(like the old Nokia dumbphones), and also has a small second battery inside it, something that can power the ram/cpu for 5 minutes.
Then, you can just yank the dead battery, plug a new one in
It would also allow for multiple battery sizes: Want a slim phone? Ok, use a small battery. Need two weeks of life? use a large battery.
Easy solution.
Specialized CPU elements have been tried. The track record to date is roughly this:
A lot of things which you might think would help turn out to be a lose. Superscalar machines and optimizing compilers do a good job on inner loops today. (If it's not in an inner loop, it's probably not being executed enough to justify custom hardware.)
We can't see it, we can only detect it by its power draw, and it makes up 95% of your chips!
I suffer from attention surplus disorder.