Nick Dalton writes:
It is now confirmed that the iPad only has the same amount of memory as the iPhone 3GS: 256 MB. Why couldn’t Apple spend a few dollars extra on a $500 device to double the memory to 512 MB? I think one answer can be found in iFixit’s teardown of the A4 processor. The memory is actually built-in to the same package as the A4 CPU. This makes for blazing fast access to the memory by the CPU, which is important when moving around large blocks of memory quickly for displaying on the screen. Having the memory chips physically close to the CPU also reduces the power consumption significantly. But cramming in the memory chips into the CPU “chip” limits the amount of memory you can have.