Is Apple going back to the PowerPC?

Hardware independence as a strategic weapon The Forbes magazine scoop that Apple is buying P. A. Semiconductor, a Silicon Valley company that designs high-performance, power-sipping PowerPC chips - the very chips Apple just migrated away from - raises a host of questions. But the people who need to worry aren't customers. It's Apple's competitors who are sweating.

Apple's hardware independence Apple has always put architectural elegance ahead of mundane commercial issues like market share. The original 16-bit Macs used Motorola 68000 processors whose architecture was much cleaner - remember the 640k memory limit on the Intel 8086? - than the scaled-up-from-8-bit Intel designs.

But Intel crushed the superior architecture with a full court press on developers that Motorola failed to match. When the IBM PC blessed the Intel architecture, Motorola never recovered.

Apple's unique legacy Unlike other personal computer companies, Apple has twice migrated its entire customer base to new architectures: IBM's PowerPC in 1994; and Intel's x86 in 2006. In both cases the migrations went remarkably well. I went through both of them.

Announcing the move to Intel, Steve Jobs said that Apple had been porting each release of OS X to Intel for years. Providing a high-performance PowerPC emulator on the Intel Macs meant that for most users the transition was virtually invisible.

But it is clear that Apple learned a bigger lesson: don't get tied to one hardware vendor.

They put that lesson to good use on the hot-selling iPhone, whose 667 MHz ARM processor runs Mac OS X and the Safari browser. Another architecture with zero impact on users.

P. A. Semi's claim to fame Hey, it's Earth Day, everybody's green. But PA Semi has been doing it longer than most.

Their PA6T-168M has 2 2 GHZ 64-bit superscalar PowerPC processors linked by a coherent cross-bar fabric, 2 DDR2 memory controllers, 2 MB of cache, and an I/O system with 8 PCI express engines - with 4 GB/sec bandwidth for each engine, 4 GigE protocol engines AND 2 10 GigE engines that include line-rate packet filtering, VLAN flow control and TCP/IP acceleration.

Whew. And the whole thing dissipates just 5-13 watts.

To get into that territory the Intel Core family has to give up clock speed, bus bandwidth and I/O performance. The 10 watt U7600 has a 1.33 GHz processor clock speed, a 2 MB cache running at 1.2 GHz and a 533 MHz bus.

OK, PA Semi has great technology. How will Apple use it?

Gazing into the Storage Bits crystal ball It's a phone! No, its a supercomputer!

Some reasonable conclusions:

• No PowerPCs in the iPhone. Those processors sip milliwatts - not watts - of power. The PA Semi skunkworks may have something in that range, but their focus has been high-performance computing - not mobile apps.
• No PowerPC MacBooks either. Too many of the pro apps have been tuned for Intel's SSE instruction set to appeal to pro users. Intel is competitive at the notebook level - although the threat will keep them honest.
• Apple TV on 'roids. All that I/O and compute would do wonders for an appliance media server. You don't want noisy fans and you DO want the ability to process 3D video, which means lots of bandwidth.

Sure, the Apple TV hasn't been very successful - yet. But as broadband reaches more homes and the studios work through their trust issues, a powerful and easy to use home media center will be a no-brainer.

One other possibility: a notebook appliance with the form factor of a MacBook Air or smaller - but without the option to run Intel optimized pro apps. But that's a stretch.

The Storage Bits take While the CPU specs are impressive, Apple has bought a superb design team whose low-power and I/O mojo are even more impressive. This is a media play, not a processor play.

But it is also a warning to competitors whose software is too tightly tied to hardware. Apple's hardware independence means they can change the game any time they want.

Like they just did.

Comments welcome, of course.

Update: to all who pointed to the public statements of Apple and PA Semi I just have one question: when did the obsessively secret Steve Jobs start tipping his hand in public? I missed that.

I'm sure the statements are true-enough-for-now - but Apple didn't pay $2 million per engineer just for mobile chip engineering - though I'm sure they're happy to have everyone believe they did. End update.