HardwareCentral - Apple's iPad Has Muscular ARMs

Apple's iPad Has Muscular ARMs

1GHz of Get Up and Go

January 29, 2010
By Andy Patrizio

The Apple iPhone has been a game-changing device in many ways, but it will never win any performance awards. Its processors are underclocked, meaning set to run slower than they can, to reduce heat and conserve battery power. The result is a phone that is decidedly lacking in pep.

But the iPad looks to be much faster. At its launch Wednesday, Apple (NASDAQ: AAPL) CEO Steve Jobs said "it just screams." Those who have had hands-on experience concur. "It is blazingly fast from what we can tell," wrote gadget blog Engadget.

"This thing is very fast," said Nathan Brookwood, research fellow with Insight 64, who attended the event. "You flip from landscape to portrait mode and before your hand has stopped moving the screen has caught up. That has not been my experience with the iPhone. So it's a very fast processor."

As is typical of Apple product launches, Jobs did not go into technical details. He simply said the iPad uses the "Apple A4" processor, which Brookwood joked sounds like the name of a highway in England.

It's not technically a CPU, either, as Jobs called it, but a System-on-a-Chip (SoC) design. Chip enthusiast site Bright Side of News revealed on Thursday a discussion its editors had with Warren East, CEO of CPU core designer ARM, during an event in Las Vegas at CES.

According the report, East said Apple is using ARM's Cortex-A9 MPCore, meaning a dual-core design, with a GPU from ARM, called the Mali 50-Series. ARM has begun pairing its CPU and GPU together as a selling point.

Apple did not return calls seeking comment.

The iPhone 3G uses a Samsung ARM design and a PowerVR graphics processor, while the iPhone 3GS, which is a little faster, uses a Samsung Cortex-A8 and PowerVR SGX GPU. The 3G processor is rated for 620MHz but runs at 412MHz, while the 3GS is rated for 833MHz but runs at 600MHz.

The A4 by contrast runs at 1GHz, and could run faster, but several Cortex-A9 licensees -- including Nvidia, which uses it in the Tegra 2 design -- have chosen to run at 1GHz for optimal balance of thermals and performance.

P.A. Semiconductor in the Mix?

In 2008, Apple acquired chip designer P.A. Semiconductor, which had expertise in making high-performance CPUs with low power draw. Since then, Apple watchers have wondered what that engineering team's role would be. Given that the A4 chip is branded as an Apple product, it would seem this is the first product to stem from that acquisition, although Apple has not stated that as fact.

It's not a whole new design but an ARM derivative, which doesn't surprise Brookwood. "I would have been very surprised if it had a P.A. Semi product in it. Even when you start with blocks from third parties, just taking an ARM core and integrating it with a GPU and putting other peripherals on a chip and getting it through a design process, all that, to do that in 18 months is really moving at breakneck speed," he told InternetNews.com.

Andy Patrizio is a senior editor at InternetNews.com, the news service of Internet.com, the network for technology professionals.