Originally posted by e1618978
If that is true, then it would be easier to move to the Pentium than the Cell processor.
Not necessarily, since Cell contains a PowerPC, and the x86 lacks both a minimum binary compatibility and AltiVec or anything comparable. SSE and clones aren't even in the same league.
Why is everyone so hot on the Cell and down on the Pentium?
Because x86 is just the same basic style as the traditional PowerPC, only more poorly designed and more fragmented.
Cell changes the rules.
More to the point, Cell uses parallel SIMD processing, um, cells
, which make it a very promising multimedia architecture. The Pentium offers all the pain of a transition to a wholly incompatible ISA, and no compelling features over a standard PowerPC core. (A fairly minor, transient speed differential doesn't count—there have been times when PowerPCs were faster, too). It would require a lot of work to get OS X to really use a Cell architecture, but at least the work would pay off with capabilities that conventional CPUs simply don't have.
I know that 8088-family assembly language is crap, but that only affects the compiler writers...
The endian issue affects everything, the lack of AltiVec severely reduces the functionality of some of Apple's basic apps and technologies, the lack of binary compatibility forces apps to be rebuilt to get any kind of performance at all, and the completely different design priorities require every app to be completely reoptimized—and possibly re-architected—to perform well
And again, this is true to some extent for Cell, but at least Cell gives us something we didn't have before, in the form of multiple, superfast SIMD cores. Also, a move to the Pentium would be a move back toward an architecture that still prefers big, single threads (even if there can be two of them now) and dual processing at best. Cell encourages multithreading and small, dedicated tasks—which Cocoa also encourages—and like PowerPCs generally, is much more MP friendly.
Having said all that, the most obvious upgrade path for the PowerMac is the 900-series PowerPC. The Power5-derived member of that family should answer any performance objections (its big brother, the Power5, certainly has) and the total amount of work required to get OS X and OS X applications running well is just about zero—it's a straight-up PowerPC. Getting the kernel to exploit FastPath, if that makes it down from the Power5, shouldn't take too much work on the part of the kernel team, and no code outside the kernel should know or care whether FastPath is there.