所周知，苹果ipad使用的a4、a5处理器来源于arm架构，不过根据近日出版的乔布斯官方传记，intel atom也是曾经有机会的，只是被最终否决了。
根据传记披露，乔布斯和苹果的工业设计副总裁乔纳森·艾维(jonathan ive)从二十世纪九十年代初就开始开发平板机设备了，专利申请也表明ipad草图早在2004年就已绘制出来，只不过从草图上仅能看出触摸屏等外部设计，内部情况始终是个谜。
2005年的时候苹果决定转向intel x86架构，乔布斯最初就计划在ipad内使用低功耗的atom处理器，不过当时的ipod部门高级副总裁tony fadell坚持认为ipad应该使用arm架构，而乔布斯坚定地认为“最好相信intel能做出好芯片来”。后来的事儿大家都知道了：苹果收购了半导体芯片设计厂商pa semi，自己开发了a4 soc，内部架构正是来自arm。
乔布斯对此非常满意，甚至告诉传记作者walter isaacson，intel在提供竞争性产品方面总是脚步太慢，缺乏灵活性。
乔布斯说：“要说高性能，intel无疑是最棒的。他们有最快的芯片，但你不能在乎功耗和成本，而且他们的芯片只是单独一颗处理器，还需要其它大量配件。我们的a4在一颗芯片内集成了处理器、图形核心、移动操作系统、内存控制器。我们曾经试图帮助intel，但他们听不进去。这么多年来，我们一直在说他们的图形技术有多烂。每一个季度，我都要带领三名高管和paul otellini(intel ceo)安排会谈。最初，我们的合作很愉快，他们也想把这种合作带到iphone处理器上。”
乔布斯进一步披露说：“合作未成的原因有二。一是他们真的太慢了，就像一艘老轮船，而我们追求高速度。二是我们不想对他们全盘托出，那样他们就会出卖给我们的竞争对手了。”
不过另一方面，paul otellini也有话说。他声称苹果和intel无法在价格，以及谁掌控开发团队的问题上达成一致。很显然，乔布斯的控制欲让intel受不了。
乔布斯称：“苹果之所以能创造出ipad这样的产品，是因为我们始终坚持技术与艺术的完美平衡。”
英文摘抄自
since the macintosh computers were now using intel chips, jobs initially planned to use in the ipad the low-voltage atom chip that intel was developing. paul otellini, intel’s ceo, was pushing hard to work together on a design, and jobs’s inclination was to trust him. his company was making the fastest processors in the world. but intel was used to making processors for machines that plugged into a wall, not ones that had to preserve battery life. so tony fadell argued strongly for something based on the arm architecture, which was simpler and used less power. apple had been an early partner with arm, and chips using its architecture were in the original iphone. fadell gathered support from other engineers and proved that it was possible to confront jobs and turn him around. “wrong, wrong, wrong!” fadell shouted at one meeting when jobs insisted it was best to trust intel to make a good mobile chip. fadell even put his apple badge on the table, threatening to resign.
eventually jobs relented. “i hear you,” he said. “i’m not going to go against my best guys.” in fact he went to the other extreme. apple licensed the arm architecture, but it also bought a 150-person microprocessor design firm in palo alto, called p.a. semi, and had it create a custom system-on-a-chip, called the a4, which was based on the arm architecture and manufactured in south korea by samsung. as jobs recalled:
at the high-performance end, intel is the best. they build the fastest chip, if you don’t care about power and cost. but they build just the processor on one chip, so it takes a lot of other parts. our a4 has the processor and the graphics, mobile operating system, and memory control all in the chip. we tried to help intel, but they don’t listen much. we’ve been telling them for years that their graphics suck. every quarter we schedule a meeting with me and our top three guys and paul otellini. at the beginning, we were doing wonderful things together. they wanted this big joint project to do chips for future iphones. there were two reasons we didn’t go with them. one was that they are just really slow. they’re like a steamship, not very flexible. we’re used to going pretty fast. second is that we just didn’t want to teach them everything, which they could go and sell to our competitors.
according to otellini, it would have made sense for the ipad to use intel chips. the problem, he said, was that apple and intel couldn’t agree on price. also, they disagreed on who would control the design. it was another example of jobs’s desire, indeed compulsion, to control every aspect of a product, from the silicon to the flesh.