Researchers Design Microchip Ten Times More Efficient

WirePosted writes to mention that a new highly efficient microchip has been announced by researchers from MIT and Texas Instruments. The new chip touts up to 10 times more energy efficiency than current generation chips. "One key to the new chip design, Chandrakasan says, was to build a high-efficiency DC-to-DC converter--which reduces the voltage to the lower level--right on the same chip, reducing the number of separate components. The redesigned memory and logic, along with the DC-to-DC converter, are all integrated to realize a complete system-on-a-chip solution."

Any chance of commercial success?

[damn_registrars]

The first thing that came to mind when I saw this article was the Transmeta [wikipedia.org] Crusoe [wikipedia.org] processor. Which unfortunately never achieved much of any significant market penetration. Indeed, it seems that you really have to have something more than just an incredibly efficient chip in order to compete against the Intel - AMD behemoth.

Personally, I would love to see a chip that requires very low power make it into the mainstream market. I think it would great to have something like that for the miniITX form factor or something of that nature that hobbyists could tinker with and find fun applications for. The Transmeta, unfortunately, never realized that as far as I ever saw.

Re:Any chance of commercial success?

[ejtttje]

I don't think they're demonstrating a particular CPU, but a technology or design strategy that can be built into *any* chip. So Intel or AMD could pick up this research with their own chips. (subject to patents and licensing of course)

Also, from the article: "So far the new chip is at the proof of concept stage. Commercial applications could become available "in five years, maybe even sooner, in a number of exciting areas," Chandrakasan says

Interesting but what about variability?

[quo_vadis]

Their work is definitely interesting, but I think some important questions remain unanswered, the main among them is the tradeoff between correctness of operation vs. performance because of variability. There is a paper in ISLPD 2006 which shows that for a 65nm circuit to operate at 0.3 V, the clock period must be scaled up by a factor of at least 230% to compensate for variability related issues. Additionally, there is a huge problem as far as tool support goes. This is not just mix-and-match style design. In order for this to have widespread use, it needs to work well in the EDA tool workflow. This means that libraries (and to some extent transistors) need to be characterized well at the subthreshold operating voltages. This causes a catch-22 situation. In order to design something using this subthreshold voltage technology, you need good transistor models, but the fabs have no interest in providing these models unless there is large customer demand. It is pretty expensive to get good models. The way this works is most fabs actually create transistors/gates at the given feature size, characterize them, including parameters for variation/process variability and give these to their customers, who design their chips based on these simulations. The reason these are so important is that for synchronous circuits, you have to base the design of the clock scheme on the worst/average case delay, and this you can get only by doing complete (usually Monte Carlo based) simulation of the chip using the transistor models that fab gives you. If you base the parameters solely on simulation based tools, you ignore all sorts of effects in the real world, causing a massive drop in yield(i.e. working chips made by fab).

Re:wouldn't you want the voltage to be HIGHER?

[LehiNephi]

You're thinking about a physics-land purely resistive circuit, where we can arbitrarily control the resistance. Unfortunately, that's not quite the case with very-much-minified microprocessors. We can't arbitrarily force a couple hundred million transistors to use less current. And at the same time, transistors can be designed so that they don't require 1000V to operate.

Every transistor leaks current to some extent. And as those transistors get smaller, that amount of leakage likes to get bigger, because the "off" resistance of the transistor decreases. There has been an awful lot of research into how to reduce the leakage, with some remarkable successes, but the problem is becoming harder as the features shrink. So in order to limit the amount of leakage, the manufacturers are working to lower the voltage required for the transistors to operate. A lower voltage across that same off resistance means less current leaking (V=IR), and so less power is lost. The fact that the power is a function of the square of the voltage (or current) means that even a relatively small decrease in the voltage means a significant power savings.

Re:Will we get these soon?

[crgrace]

Putting a power amplifier on the same chip as a radio transmitter has not been successful. A lot of money has been wasted going down that road so far...

Re:wouldn't you want the voltage to be HIGHER?

[vsage3]

You're assuming R is independent of applied voltage, which is not true for any transistor. Resistance is a derived quantity that can be (for example) formulated in terms of the ratio of resulting current from an applied voltage. Ultimately, electronic devices require a certain current to operate, so it's not as simple as minimizing power by arbitrarily scaling down current. If you cannot supply enough current to a system, transistors may not have enough juice to produce those 1's and 0's quickly enough, causing unreliable operation. A more accurate way to look at the problem is that if you wish for a device to operate and it requires a given current, if you can find a way to deliver this current at a lower voltage then you will require less power to run the device.

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Re:Will we get these soon?

[Serveus]

The thing about this is body heat is not a source of power. To have a source of power (for a thermocouple to work) you need a temperature differential, so you would need a part of the thermocouple sticking out of your body. Another thing is no matter how low the current drawn from batteries is they still need changing batteries only have a limited shelf life (with no current drawn.) Lower power means smaller batteries but I dont think thermocouples are a viable source of power for implants, perhaps they can get power from motion.