Intel Ponders Solar-Powered CPU Tech in Graphics, Memory

Intel's experimental solar-powered processor may have started off as a fun project, but the chip maker is now looking to extend the technology to hardware such as graphics processors, memory and floating point units.

Intel last year showed the low-power processor -- charged only by the light from a reading lamp -- running Windows and Linux PCs. Intel is expected to share further details about the processor, which is code-named Claremont, at the International Solid-State Circuits Conference in San Francisco next week.

The CPU, which is the size of a postage stamp, is also known as the near-threshold voltage (NTV) CPU for its ability to keep operating at extremely low voltage levels. The CPU's power consumption could go down to as little as 280 millivolts when running at 3MHz, and up to 1.2 volts when running at around 1Ghz when more performance is needed.

The NTV CPU is designed to bring extreme energy efficiency to computing devices, said Justin Rattner, Intel's chief technology officer, in a briefing ahead of the show.

"It's allowing us to make Intel's product more [power efficient] across the compute continuum" while reaching appropriate performance levels, Rattner said.

The CPU can remain at near-threshold voltage levels when not operational, which could keep laptops operational without killing battery life. That is much better than putting a PC into sleep or hibernation mode to save battery.

In an on-stage demonstration at last year's Intel Developer Forum, an engineer demonstrated a PC running a small animation when powered by the CPU. After the light source was blocked from the chip, the computer froze. The CPU worked with concept DDR3 memory developed by Micron called Hybrid Memory Cube, which is seven times more power-efficient than current DDR3 memory.

"It was not our intention to build a solar-powered microprocessor," Rattner joked, reminiscing about the experiment.

But the demonstration was an interesting way to show what the company was trying to achieve with NTV technology. The energy gains are about five to 10 times with NTV, Rattner said.

"The design has generated an extraordinary amount of interest," Rattner said.

The next goal is to extend the technology to other key components inside a computer.

"We are continuing to expand the use of these low-voltage techniques ... to graphics and memory," Rattner said. The technology can also be deeply embedded inside circuitry to bring more power efficiency to supercomputing.

The solar-powered CPU is based on a Pentium chip design, and the researchers converted the logic circuit to operate at near-threshold voltage. The CPU was made using the 32-nanometer processor, which is the same used to make Intel's latest smartphone chip code-named Medfield. That chip will be appear in smartphones and tablets later this year.

Intel is sharing details about the chip layout and design methodology at ISSCC, which is being held from Feb. 19 to Feb. 23. The chip maker is also presenting separate papers that cover memory, graphics processors and floating-point units based on near-threshold voltage technology.

The research around the solar-powered CPU is being carried out in Intel's research labs. The chip maker has said it does not expect the solar-powered CPU to go commercial, but that elements from the research would be implemented in future Intel products.