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Details on Apple's ARM-based 'A4' Chip Begin to Surface

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Bright Side of News reports on Apple's "A4" chip unveiled as the brains behind the company's new iPad tablet device. Unsurprisingly, the CPU included in the chip is based on the ARM Cortex A9 licensed by Apple and implemented by its team of chip designers acquired as part of its 2008 purchase of P.A. Semi.
A4 is a System-on-a-Chip, or SOC, that integrates the main processor [ARM Cortex-A9 MPCore i.e. Multi-Processing Core, identical to ones used in nVidia Tegra and Qualcomm Snapdragon] with graphics silicon [ARM Mali 50-Series GPU], and other functions like the memory controller on one piece of silicon - not unlike what Intel is trying to achieve with its future "Moorestown" Atom processor that debuted inside LG's Smartphone.
Click to expand...
As noted by Apple CEO Steve Jobs during the iPad's introduction, the A4 runs at 1 GHz, the same as the Cortex A9 CPU found in NVIDIA's Tegra and Qualcomm's Snapdragon platforms. The Cortex A9 design is actually capable of operating at up to 1.3 GHz, but Apple and others utilizing the chip design have all opted to downclock the CPU to 1 GHz in favor of better thermal performance.

In contrast to the iPad, the iPhone 3GS utilizes a Cortex A8-based CPU running at only 600 MHz. The significantly improved horsepower of the A4 found in the iPad, as well as other improvements included in Apple's system-on-a-chip designed in-house, serve to provide substantially better performance and capabilities compared to the iPhone.

Article Link: Details on Apple's ARM-based 'A4' Chip Begin to Surface
 
I was actually excited about the 'bespoke' processor, but it seems that it is just a rebranded Nvidia... is it?
 
Can't wait to see what the A3 or A5-powered iPhone 4G will be capable of.
 
kernkraft said:
I was actually excited about the 'bespoke' processor, but it seems that it is just a rebranded Nvidia... is it?
Click to expand...

What were you expecting? Do you really think Apple could just give you a completely new CPU architecture out of the blue? People should lower their expectations to level that makes sense. It's not fringe science, it's reality.
 
2 cores but not multi threaded!

While parts of the iPhone OS and some Apple Apps like Safari may be able to exploit dual cores, I suspect one core is powered down most of the time (perhaps always).

One can only hope that this version of the OS is the bridge to real multi-tasking.

Aside: Would love to know if anyone has seen iWork in action on an iPad. Numbers and Pages are often sluggish on my Mac Pro. I see a need for real horsepower here.
 
Wrong information

The Tegra & Snapdragon are only similar together and do NOT feature Cortex-A9 based design featuring multi-core or SMP like the Tegra2, TI OMAP 4420/4430.

Tegra & Snapdragon are based (loosely) off a Cortex-A8 design which is multi-chip not a multi-core cpu .... completely dissimilar.

PA Semi, nor their majority stake holders, Apple Inc, would waste time with an older chip reference design like the Cortex-A8 that iPhone 3GS uses.

I read elsewhere this is almost identical in design to the Tegra2 and both are EXTREMELY POWERFUL in terms of OpenGL ES performance (OpenGL as well), and video strength.

BTW, Tegra2 platform will be featured in all new Audi cars made in 2010 as 2011 models - that includes the new A8, S5, A4/S4, A6/S6, etc.
 
Povilas said:
What were you expecting? Do you really think Apple could just give you a completely new CPU architecture out of the blue? People should lower their expectations to level that makes sense. It's not fringe science, it's reality.
Click to expand...

Well, they could have used Atom... :)
 
I just posted this on the Unity forums but figured I would post here as well. I'm not sure who came up with the guess on the GPU but it must have been a financial analyst as it certainly wasn't an engineer or developer. Why?

I am highly suspicious of their ARM Mali 50 series claim for the GPU (obviously I could be wrong) because that would make it quite inferior to the iPhone 3GS.

With vertex processing ARM Mali-55 pushes 1M poly/sec wheres the SGX535 does 28M poly/sec... even the smallest SGX520 does 7M poly/sec. Comparing fillrate you see a huge gap again with 100M pix/sec for the Mali-55 and 400M pix/sec for the SGX535 (someone please correct this number if it is incorrect, I know that 400M is the floor possibility but this might possibly be 800M pix/sec in their marketing by using two pipelines with a scene depth complexity of 2.5)

Apple has a significant investment in PVR technology (both as a key investor owning 9.5% of the company and in their existing technology) so I see little reason to move away from that. Not to mention that they would lose the PVR specific extensions by moving to another technology.

If they were looking at ARM GPU technology I don't see how they could use anything less than the ARM Mali-400 dual-core which would yield theoretical 30M poly/sec, 550M pix/sec and is roughly the equivalent chip to the one in the iPhone 3GS. Since they are designing the SOC in-house why would they vendor lock to strictly ARM to get the exact same thing they already have with a 3GS?

I do not see why Apple would switch away from PVR at this point, especially since the iPad is made to run iPhone applications. As soon as you have different GPUs you not only have completely different drivers but also completely different driver bugs. If you wanted to have things run flawlessly you would expect them to be using a PVR chip.

So needless to say I'm a little sceptical here.
 
Better "capabilities" would imply that they would use the chip to make a iPad OS that isn't the same as an iPod Touch :).

I think it's pretty easy to see what happened here.

  • Stock Holders expected to see a Tablet.
  • Apple didn't want to spend too much on R&D
  • Apple wanted the HUGE money stream from the app store
  • Apple wanted people to still buy MacBooks
  • Apple didn't want to make the 1st gen too good, to ensure future iPad sales years down the road

I'm sure some folks at Apple had some AMAZING ideas about how to make this tablet. Too bad Steve Jobs didn't listen, and just wanted to Max Profit. :rolleyes:
 
indigo144 said:
While parts of the iPhone OS and some Apple Apps like Safari may be able to exploit dual cores, I suspect one core is powered down most of the time (perhaps always).

One can only hope that this version of the OS is the bridge to real multi-tasking.
Click to expand...
Multi-threading and Multi-Core really have nothing to do with Apple's decision to not allow user multi-tasking. Underneath the hood the iPhone OS very much a multi-threaded OS. Apple has simply designed to only allow one user application to run at the same time.
 
So Apple is going the Cortex A9 MP route, nice.

Now if they would just put this sucker in the iPhone 4G we'd be all set. The iPhone 4G is looking better and better everyday.:D
 
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