Nvidia’s latest Tegra mobile chip has hidden super powers courtesy of a secret very low-energy fifth core
For months, Nvidia has boasted that its upcoming next-generation Tegra chip – code-named “Kal-El” (Superman’s Kryptonian name) – would be the first mobile chip with four cores.
Evidently, they lied: the chip for smartphones and tablets will actually have five cores.
In white papers and a blog posting, Nvidia said Kal-El will feature a “companion core” that will run at a lower frequency than the other four and will operate at exceptionally low power. The fifth core will be used to run the Kal-El-powered devices at low power while in standby mode, and will also run tasks that do not need all the power of the other four cores.
“During less power-hungry tasks like Web reading, music playback and video playback, Kal-El completely powers down its four performance-tuned cores and instead uses its fifth companion core,” Matt Wuebbling, director of product marketing for Nvidia’s Tegra business, said in a posting on the company’s corporate blog. “For higher performance tasks, Kal-El disables its companion core and turns on its four performance cores, one at a time, as the work load increases.”
The technology – which Nvidia calls its “Variable SMP architecture” – is transparent to the operating system, which means that neither the OS nor applications need to be redesigned to take advantage of the fifth core, Wuebbling said. The chip is made via a special low-power silicon process, according to one of Nvidia’s white papers.
The four primary cores are built using a standard silicon process, enabling them to reach higher frequencies than the companion core. All five are built on ARM Holdings’ Cortex-A9 design.
Nvidia, along with other mobile chip makers like Qualcomm and Texas Instruments, already offer dual-core chips for the booming smartphone and tablet markets. Nvidia executives have been boasting that the 40-nanometre Kal-El chips will be the first with four cores. Now the number of cores has been pushed to five, and despite the growing number of cores, officials said in a white paper that the primary quad-core CPU architecture in Kal-El uses less power and offers a higher performance-per-watt metric than single- and dual-core chips from competitors.
“In order to meet peak performance demands in a multitasking environment, a single core CPU not only runs at higher clock frequencies and voltages than a multi-core CPU, but also takes longer periods of time to complete a given task,” Nvidia officials wrote. “Multi-core CPUs are able to use symmetrical multiprocessing and distribute workload across multiple CPU cores. Due to workload sharing, each CPU core can run at lower frequency and voltage to complete a multi-threaded task, or multiple tasks in a multi-tasking scenario.”
In the same vein, because of lower operating frequency and voltage, each core consumes less power, extends battery life and offers higher performance per watt than single-core CPUs, they said.
In its other white paper, Nvidia outlined the technology in the companion core. Nvidia announced earlier this month that it had begun shipping the next-generation Tegra chip, and expected devices powered by the technology to hit the market later this year.
Nvidia made its name with its graphics technology for visually intensive games, but in recent years has been making a push with its Tegra CPUs into the highly competitive smartphone and tablet spaces. Nvidia, like Qualcomm, TI, Samsung and others, is using designs from ARM to build their mobile chips.
During a conference call earlier this month to provide an update on the company’s financial outlook, Nvidia executives said they expect to see revenue for their fiscal year 2013 – which begins 30 January, 2012 – at $4.7 billion (£3bn) to $5 billion (£3.2bn), more than analysts had predicted. President and CEO Jen-Hsun Huang said the strong numbers are due to both its graphics and mobile chip offerings.
“We see growth across our entire GPU and mobile-processor business,” Huang said in a statement. “The future for computing is visual and mobile, and we are well-positioned to lead in this new era.”
The mobile chip space is about to become even more competitive, as x86 chip vendors Intel and Advanced Micro Devices look to muscle their way in. Intel is the more aggressive of the two, already seeing its chips appear in tablets and expecting Intel-powered smartphones to begin hitting the market in 2012.
Along with the five-core Tegra chip, Project Kal-El also includes a new 12-core graphics processor that will offer three times the graphics performance of Tegra 2. It also will have more capabilities, though Nvidia officials offered no details on those.