As best we know TSMC is the sole fabricator of Apple's A8 chips on 20nm process, but so far from what DigiTimes has been able to determine that is not the case for the upcoming A9 chips.  TSMC plans to keep pricing the same as they move to 14nm process tech but both Samsung and GLOBALFOUNDRIES are in a position where they could decide to drop their pricing in order to win business.  Qualcomm has already placed orders for its 14nm chips with TSMC and Samsung but it is possible that with the experience GLOBALFOUNDRIES has with the 14nm process thanks to business from AMD they may also be able to undercut TSMC's pricing, assuming their yields can stay up.

"Globalfoundries is striving to be among the major contract chipmakers of Qualcomm and Apple, vying for 14nm chip orders from the two vendors, according to industry sources."

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