iPad – Details on the processor and what’s hot

[Editor’s note: We have updated this article on 28 Jan 2010.]

Okay so the iPad is the name. I was hoping they would surprise us with something new and clever. Not! Clearly Jobs is a fully mature human being now, having gotten completely past Scully and the Newton MessagePad. So contrary to my earlier statement that he would distance the new device from the word “pad” Jobs’s new toy is in fact called the iPad. I have to admit it actually is better sounding than iSlate and iTablet…neither of which I cared much for.

The iPad – Details

The Apple iPad webpage just went live about 60 seconds ago. I’ve been reloading Apple.com for minutes now every 15 seconds. Hurray! It’s up. I have much to do today I’m going to make this blog post pretty short. The details that matter to us at Architosh are centered around this device’s raw power to handle large document images both in viewing capability and creation.

The A4

Apple is calling the new internally designed main processor (CPU) the A4. This is a PA Semi team produced chip, make no bones about it. This group has world-class expertise in high-performance/high-energy efficient chip design. That’s why Apple acquired them. That is why the US Government got hold of some of their first processors for military equipment–because they were that good.

Apple's PS Semi produced A4 processor in the new iPad. 1 Ghz chip may integrate graphics in a system-on-a-chip package. The A4 is likely based on a customization of an ARM processor design as Apple holds a special class license to ARM architectures which enables them to modify architectures.

The Apple A4 runs at 1-Ghz. It’s high-performance, lower-power system-on-a-chip custom silicon. We’ll have to dig around to find out who manufactured it and that will likely be easier to obtain than the internal architecture of the chip. That Apple will keep very close to their chest. We assume it is ARM architecture-based, but that’s not taking us all the way to where we really want to go.

Some of the details we now appear to know are flowing in across various sources on the Net. Engadget is claiming the A4 design is not just ARM architecture based, as we mentioned above, but based on the very latest Cortex A9 series multicore architecture. This chip was first discussed by ARM back in mid year 2009.

The ARM Cortex A9 can be up to a Quadcore multicore chip, as seen in this diagram. Credit: ARM.

Key to the Cortex A9 architecture is that like the Cortex A8 (which the iPhone processor is currently based around) the A9 is multicore. Additionally, it is built on a 45-nanometer processes compared to the 65-nanometer process of the A8. This reduction in chip size decreases power consumption while enabling the chip to speed up. Unlike Intel’s Atom chip, the ARM Cortex A9 sips power at about 300 milliwatts or less, while the Atom uses up to 2 watts. 2 watts is tiny in the world of chips coming from Intel, but not as tiny as what is needed in cell phones. That explains why the Atom is hot with Netbooks but not with Apple.

If Engadget is correct about the Apple A4 being Cortex A9 based the next question to ask is does the A4 have two cores or four? And if  the A4 is indeed Cortex A9 with a quad core why isn’t Apple bragging about that? Seems like it is right up their alley.

Could it be that the number “4” in A4 stands for quadcore?

Graphics

In terms of graphics Apple is providing no information on the GPU. So we can only imagine what is inside powering that gorgeous LED backlit display, which supports 1024 x 768 resolution max. With that display size one can really bring up pretty big PDF files of CAD or 3D images. That’s much better than doing it on the iPhone–something I’ve done quite often but not like I’d like due to some performance and screen size limitations.

Now looking through the lens of the ARM Cortex A4 as the likely customized engine in Apple’s A4 processor we have learned a bit more. This C/Net article says the Cortex A4 can handle 1080p high-def video but Apple’s spec and iPad pages do not claim this. Video seems to be limited to 720p.

Given what we think we know details of the A4 chip may consist of this:

• 1 Ghz frequency custom designed Apple CPU (via PA Semiconductor team)
• ARM Cortex A9 Multicore Architecture
• Quadcore (hence A4 name) or dual core only
• 1-2 MB of L2 Cache
• Single and double precision scalar Floating-Point (FPU)
• NEON Media Processing Engine (not sure…)

Anyway, until we learn more… In the meantime please enjoy the iPad pages at Apple.