“During the Apple product introduction last Tuesday, Tim Cook mentioned that the heart of the new iPhone 5S was the A7 chip, which contained a billion transistors. The size of the chip grew from 96 sq. mm for the A6 to 102 sq. mm for the A7,” Russ Fischer who spent 35 years in the semiconductor industry, wrties for Seeking Alpha.
“Experts at Chipworks who claim to be familiar with the Apple ‘A’ chip part numbering system suggest that the early peeks at the A7 chip indicate that it was made at a foundry other than Samsung,” Fischer writes. “It appears that to get 1 billion transistors on a 102 sq. mm chip would require something much better than the 28nm processes available at either TSMC or Samsung.”
Fischer writes, “The Ivy Bridge HE-4 is made on the Intel 22nm Trigate process and has 1.4 billion transistors with a chip size of 160 sq. mm, so a billion transistor logic chip on 22nm should be around 114 sq. mm. “Hand packing” the A7 design might give another 10% size improvement, which would make the A7 chip almost exactly 102 sq. mm. on the Intel 22 nm process.”
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