No, this isn’t about standard paper sizes, but the processor chip in the iPad.

I was puzzled that Apple had gone to the trouble and expense of doing custom silicon, and I’m still puzzled. So — according to this NYT report — are other observers.

But designing its own processors burdens Apple with additional engineering costs and potential product delays. It also forces the company to hire — and retain — experienced chip designers. Several who joined the company in 2008 after an acquisition have already left for a secretive start-up.

Though chip industry experts have yet to put the iPad through their customary rigorous tests, Apple’s demonstrations left them underwhelmed.

“I don’t see anything that looks that compelling,” said Linley Gwennap, a chip analyst at the Linley Group. “It doesn’t seem like something all that new, and, if it is, they are not getting far with it.”