[The Godfather]

If you have been following the iPad related posts in the Unofficial Apple Weblog, you might have learned that (in chronological order):

+The A4 was created from scratch by Apple
+It required the purchase of PA Semi and its brain-might
+It is yet another ARM9 CPU
+It may contain a graphics accelerator nobody has ever heard about
+It definitely uses the PowerVR SGX

...the same specs as the Texas Instruments OMAP3, which powers the open hardware Pandora handheld: three year old technology.

How is this an advantage over the Tegra or the Kirkwood?

[imitchellg5]

What was supposed to be so special about it in the first place?

[Wiskedjak]

It's a CPU. As long as it smoothly runs the software it's supposed run, it doesn't need to be special. Honestly, I think some Mac people desire too much to return to a state as with the PowerPC, where they could define the difference between Apple and everything else by the hardware when, really, the difference is in the software and the sexy packaging.

[imitchellg5]

Originally Posted by Wiskedjak 

It's a CPU. As long as it smoothly runs the software it's supposed run, it doesn't need to be special. Honestly, I think some Mac people desire too much to return to a state as with the PowerPC, where they could define the difference between Apple and everything else by the hardware when, really, the difference is in the software and the sexy packaging.

I couldn't agree more. Hardly anyone cares about what sort of processor is in the iPhone or iPod touch. As long as it can run the processor smoothly and efficiently, that's all we need. IMHO, it's surprising that Jobs even mentioned it during the keynote.

[The Godfather]

On the other hand, it uses the latest generation PowerVR SGX, which adds OpenCL. It could be enabled officially with the next SDK.

In theory, it could boot Ubuntu, since it has the same CPU and similar video circuits.

[Simon]

Yep, with this type of device nobody (minus a few geeks like us) will give a damn about the CPU, the GPU, or any other spec. As long as it runs stuff well and comes with great apps people will enjoy it.

And what's the one thing that has consistently been reported by all the people who have had hands-on time with the device? That's right. It's super fast and the GUI is very smooth. Exactly the stuff that matters.

[tupsy0]

There must be a lot we still don't know then because it's supposed to have cost them up to $1 billion to develop. According to Apple they couldn't find a CPU that did exactly what they wanted so they made their own.

[turtle777]

My guess is that the power management is far superior to other chips in its class.

-t

[mduell]

Originally Posted by The Godfather 

+The A4 was created from scratch by Apple

Did TUAW actually claim this? I'm surprised anyone would guess that.

Originally Posted by The Godfather 

+It is yet another ARM9 CPU

It's ARM11 (based on Cortex-A9), not ARM9.

Originally Posted by The Godfather 

+It definitely uses the PowerVR SGX

No surprise there, since they're already familiar with it in the 3GS.

Originally Posted by The Godfather 

...the same specs as the Texas Instruments OMAP3, which powers the open hardware Pandora handheld: three year old technology.

You mean OMAP4, TI's shiny new chip combining Cortex-A9 and PowerVR SGX.

Originally Posted by The Godfather 

How is this an advantage over the Tegra or the Kirkwood?

My guess is the differentiation will be an aggressive approach to power management and accelerator choice (optimized for the whole H.264 pipeline, no support for WMV/VC-1).

[analogue SPRINKLES]

Blaa blaa blaa. Who cares. Everybody who touched the iPad said it was the fastest handheld they have ever used. No delays. The iPhone 3Gs is also pretty damn snappy as it is. Nothing out there we can get anyway.

The big point with the A4 is that it is fast but uses VERY LITTLE POWER. Read up about the high quality display the iPad uses, they are power hogs so it is nothing short remarkable they managed to get 10 hours out of it with that combo.

[The Godfather]

Originally Posted by mduell 

Did TUAW actually claim this? I'm surprised anyone would guess that.
It's ARM11 (based on Cortex-A9), not ARM9.
No surprise there, since they're already familiar with it in the 3GS.
You mean OMAP4, TI's shiny new chip combining Cortex-A9 and PowerVR SGX.
My guess is the differentiation will be an aggressive approach to power management and accelerator choice (optimized for the whole H.264 pipeline, no support for WMV/VC-1).

Nice spanking, but you must note that the OMAP3 also integrates an ARM CPU and a PowerVR SGX, although of slightly lesser power, thus making it more evolutionary rather than revolutionary.
I appreciate the focus on energy efficiency, and probably silicon efficiency, but they didn't need to swallow a PowerPC company like PA Semi to achieve this. Existing Apple engineers were entirely capable of adding up the standard parts that now make the A4.

[Simon]

But you are aware that Apple has more than enough cash ($25 billion right now actually) available for acquisitions, right?

[Spheric Harlot]

The custom power management is not off-the-shelf.

This is Apple's first own development. Obviously it's not going to have branched off too far, yet. The point is that they can do whatever they want now, without having to convince any outside party that what they're asking for is viable for the chip maker. In fact, it doesn't need to be viable at all - as long as the final product is good for Apple's bottom line. And chip development is *expensive*.

Also, whatever optimizations/customization Apple may demand of future lines would invariably benefit competitors as well if the know-how were developed/maintained out-of-house. This way, it's Apple's alone.

[glideslope]

Originally Posted by imitchellg5 

What was supposed to be so special about it in the first place?

The A in A4.

[The Godfather]

From the horses mouth: the two benefits in the A4 over off the shelf CPUs are energy management and independence from other chip manufacturers.

Originally Posted by Tim Cook

http://www.appleinsider.com/articles...ssor_more.html
Unsurprisingly, Cook said that future Apple products will feature custom-built chips, much like the new A4 processor found in the forthcoming iPad. He said Apple became wary of purchasing chips from other companies designed for different tasks.
"We felt that we had the best knowledge of what we wanted the silicon to do," he said.
By designing its own silicon, he said, Apple can create chips that are best-suited for the company's products, allowing them to run cooler and more power efficient.
"Apple has, for years, been in the silicon design business," he said. "When we were on the PowerPC architecture, Apple always personally crafted the northbridge and southbridge chipset, and so it's not new to us."

See it as a direct benefit to Apple, which will trickle to us. However, by investing in an A4 future, Apple gets into competition with Texas Instruments, Marvell, Freescale, Philips, etc. By becoming practically its own monopolistic supplier, Apple better lead the ARM architecture performance race, or we will see ourselves buying slow iPhones in comparison to fast Droids in 2015, kind of like when we were buying G5s in the Core Duo era.

[Spheric Harlot]

It won't matter, because ideal integration and custom adaptations will trump raw speed.

"Fast enough" is always fast enough.

[Simon]

Well obviously Godfather was talking about a situation where they wouldn't even be 'fast enough' anymore. Software always evolves. Hardware has to do so accordingly. By bringing this development in-house and becoming a de-facto monopoly they haven't chosen the easy way.

In any event, competition from Droid et al. is an excellent thing for Apple customers.

[The Godfather]

OTOH, keeping the developers strictly compiling for ARM and an OSX API could allow them to jump to another ARM SOC if need be, if Apple can't keep up.

[lpkmckenna]

Originally Posted by Godfather

It is yet another ARM9 CPU

Originally Posted by mduell 

It's ARM11 (based on Cortex-A9), not ARM9.

You're both wrong, the A4 is a 1GHz custom SoC with a single Cortex A8 core and a PowerVR SGX GPU, says Jon Stokes: The A4 and the A8: secrets of the iPad's brain

[mduell]

I saw that last night and pounded on my head. It's a 3 year old chip, stripped down and overclocked.

[Spheric Harlot]

And, by all accounts of people who've used the thing, it's DAMN FAST.

[greenmymac]

of course this is all rumor right? We don't know exactly what the Chip is until we get our hands on it

[The Godfather]

The OpenCL feature could be a big deal, once unlocked in the SDK, or if Apple licenses PhysX for the free use amongst iPhone game developers.

[The Godfather]

Actually, because of its off-the-shelf-IP nature, the iPad will be more hacker friendly. Linux will be eventually ported to it.