(Image courtesy of AppleInsider)

A lot of the excitement about the iPad after its unveiling at in late January had to do with its custom, Apple-designed A4 processor -- but a new report says that the chip may in reality be nothing “to write home about.”

AppleInsider is reporting on the new findings by Jon Stokes of Ars Technica, who wrote over the weekend that Apple’s custom 1GHz system on a chip for the iPad is really just a single Cortex-A8 CPU with a PowerVR SGX GPU. If that sounds familiar, it’s because the Cortex-A8 CPU is the same chip used in the current iPhone 3GS -- although the handset is clocked at 600MHz, while the iPad’s Apple A4 is reportedly 1GHz.

"In all, the A4 is quite comparable to the other Cortex A8-based SoCs that are coming onto the market, except that the A4 has even less hardware," the Ars Technica report claims. "The iPad doesn't have much in the way of I/O, so the A4 itself can do away with the I/O that it doesn't need. In contrast, the typical Cortex A8-based SoC has more I/O hardware than a mobile phone can use, because you never know what customers will need which interface types."

“So why bother with custom silicon?” AppleInsider asks. The answer appears to lie in what the iPad is lacking, rather than what it actually offers. By removing some features commonly found on other Cortex-A8 devices such as a built-in camera, “Apple has probably ditched some dedicated image processing blocks.”

"With one 30-pin connector on the bottom and no integrated camera of any kind, the A4 needs a lot less in the way of I/O support than comparable chips that are intended for smartphones or smartbooks," Stokes continues. "This means that the A4 is just a GPU, a CPU, memory interface block (NAND and DDR), possibly security hardware, system hardware, and a few I/O controllers. It's lean and mean to a degree that isn't possible with an off-the-shelf SoC."

Such a revelation would likely explain the absence of a built-in camera on a device whose larger screen obviously cries out for one for such tasks as video conferencing. Recent reports have claimed that Apple has spent about $1 billion to design the custom silicon for the iPad, with those who have actually used the device claiming that the lightning-fast speed makes the zippy iPhone 3GS look positively sluggish by comparison.