death-of-powermac

Death of PowerMac?

It may be a sad day for PowerPC lovers indeed

Apple is apparently to use Intel chips exclusively. This isn't a huge surprise; IBM has been failing to deliver better PowerPCs for some time (cooler 970s(G5s) for laptops, multicore chips and higher frequencies; Jobs promised 3Ghz by the end of last year), and i386 ports of MacOs X have been talked about for some time.

Of course, this may not be a switch to the 386. Apple may want Intel to manufacture PowerPCs for them, possibly even in conjunction with IBM and Motorola FreeScale, the current manufacturers. Or they may want a chip custom-designed. They may even want to become the Itanium/IA64/Merced/whatever-it's-called-this-week's patron. But Pentium M looks like the most obvious target.

Why is this a bad thing? The 386 line is aging, and keeps itself interesting only by virtue of high clock-speeds and continuing messing-around by Intel and AMD. Now, the clock-speed route of expansion is effectively dead, a little sooner than they thought it would be, and dramatic improvements through pipeline change and so on seem improbable. Multicore is the only way to go. The 386 was never designed to scale this far.

The PowerPC, on the other hand, was designed from the ground up to be extremely scalable, and has delivered on this. The Power4 derived G5 has a bit of life in it still, and there's certainly potential for Power5 based chips, multicore chips and Cell (a PowerPC variant) on the desktop. Here's a Pentium 4 / PPC970 technical comparison. The platform has expansion room left, and improvements in compilers should help too; current gcc for PPC is apparently not so good at creating code for the chip's AltiVec vector processing unit, which gives huge boosts when it can be used.

If this happens, it'll make Mac the latest of many to move away from existing RISC platforms drawn either by the 386 (or 64bit version thereof) or the promise of the Itanium. HP/Compaq scrapped the DEC Alpha inherited from Digital, with the last version released in early 2004. HP recently bumped up the clockspeed and cache of their PA-RISC chip, and abandoned future improvement. Both went in favour of the Itanium. MIPS, the chip used by SGI and in the PlayStation 2, among others, looks likely to go the same way. Sun has de-emphasised its SPARC in favour of the AMD Opteron, an AMD64 386 extension. And now Apple seems to be going the same way. The Itanium seems to be an impressive chip, but it does mean that Intel has been given an effective monopoly on high-performance computing, and that has not historically helped innovation. IBM, of course, continues to use its own PowerPC, as do a few other customers.

Why are they doing it? Presumably because of the trouble they've had getting modernised PPC970s from IBM and the inadaquacy of the G4 platform from Motorola FreeScale that they use in their laptops. (In particular, they want to bring in laptops with HD display panels, yet their current G4s are incapable of playing back large HD content. It's a pity, and it seems short-sighted to me, if this really is what they are doing.

Presumably if they do go for a 386 they'll still leave the platform somewhat non-standard; it would be disasterous for them if Windows users were able to switch to their (far superior) MacOS X without platform change.

Conclusion here