X-ray of iPad Apple A4 chip reveals 512 MB of RAM

//addition1
It's since been shown that the iPad actually only has one layer of RAM, hence it has 256 MB of memory, not 512 MB.

Just as some people are playing with their lovely new iPads, others are carefully taking them apart to find out how they're made.

In terms of basic strip down, iFixit has performed one of the neatest dissections, discovering that the iPad has two batteries in parallel that provide 5.5 times the capacity of the iPhone.

One result is that the iPad won't charge via USB however.

In terms of the silicon guts, analysis and x-rays of the custom Apple A4 show it's been fabbed by Samsung and comes with two layers of RAM, giving a total of 512 MB.

That's twice as much as an iPhone 3GS. Of course, that's to be expected as the screen resolution is more than four times.

In terms of performance, benchmarking the iPad's OpenGL ES performance suggests it has a capability of 1.83 million triangles per second.

That compares to 2.15 million/sec for the MacBook Air (which runs on a 1.6 GHz Intel Core 2 Duo CPU with 2 GB of RAM) and 0.423 million/second for the iPhone 3G (ARM1176 clocked at 412 MHz with a PowerVR MBX Lite GPU).

As for the question of what's the exact GPU within the A4, that's still open to debate.

We know it's an ARM Cortex-A8 CPU with a PowerVR SGX-based GPU, but whether the SGX is a 52x one pipe part, a 53x two-pipe part or a 54x four pipe part is still open to debate.

//addition2
It's since been shown that the SGX part is a 535, which is the same as in the iPhone 3GS.

[sources: iFixit & AppleInsider]