Two more ICs on the front of the logic board:

57A6CVI

Qualcomm QFE1100 Envelope Tracking IC

Based on alleged schematics leaked last month, the rumor mill had the A9 pegged at a 15% smaller die size from the A8. We can't confirm the die size, but the A9 package itself appears bigger—roughly 14.5 x 15 mm, up from 13.5 x 14.5 mm on the A8. That could represent a smaller die plus the addition of the embedded M9 and other functions.