Jim Keller, the man who developed within Apple the A4/A5/A5X chips found in the iPad, iPhone 4, iPad 2, iPhone 4S and iPad 3, left company to join AMD. There he will work under the command of Mark Papermaster, a former Apple engineer who was fired by the company after the start of the Antennagate scandal, which focused on the problem of the iPhone 4 terminal losing signal if the lower left side is covered. For Apple, the loss could prove to be important in the future because in the iPhone 5 a chip developed by Keller will surely be implemented, but in the iPad 4 the development process continues.
Keller was most recently a director in the platform architecture group at Apple focusing on mobile products, where he architected several generations of mobile processors, including the chip families found in millions of Apple iPads, iPhones, iPods and Apple TVs. Prior to Apple, Keller was vice president of design for PA Semi, a fabless semiconductor design firm specializing in low-power mobile processors that was acquired by Apple in 2008. While there, he led the team responsible for building a powerful networking System on a Chip (SoC) and its integrated PowerPC processor. Keller previously worked at SiByte(R) and Broadcom as chief architect for a line of scalable, MIPS-based network processors that supported 1Gig networking interfaces, PCI and other control functions. Before Broadcom, he spent several years at AMD, playing an instrumental role on the design team responsible for the groundbreaking AMD Athlon(TM) 64 and AMD Opteron(TM) 64 processors, which featured the world's first native x86-64 bit architecture.
The chips of the A series developed by Apple enter in performance others in the same category and are extremely close in performance, in the real world, to the quads implemented in Android smartphones and tablets. Apple managed to develop very powerful hardware for its terminals, Keller was a key man in the company's gears, but now others will take his place and I hope they will do at least as good a job.
