(http://i43.tinypic.com/2cqz5ux.jpg)
The silkscreen on the production A4 reads:
APL0398 339S0084 YNL215X0
K4X2G643GE N26CGM0T
The leaked prototype has these markings:
APL0398 339S0084 YNE07423
K4X2G643GE GSA1400A
The two numbers that are different are likely manufacturing numbers (each lot of chips is stamped with a unique number to track them through the supply chain). The important numbers are:
APL0398 339S0084 <– Apple A4
K4X2G643GE <– 256 MB Samsung DRAM (two dies)
Our engineers are not surprised by this finding. We were very impressed by the extraordinarily low power consumption of the iPad, and remarked at the time that its power consumption and board design was much more in line with handheld devices than laptop computers.
source:.iphonehellas