When Apple announced that they would be moving the Macintosh over to the Intel processor architecture, the first queston many people cried in dismay was, "why not move to the Cell?!" Why not, indeed.
Apple felt the need to move away from the PowerPC for a variety of reasons. Production yield was often low, preventing Apple from getting the CPUs needed to move machines out the door to meet demand. The roadmap was worrisome; the heat of the G5 left Apple without a solution for a near-term power boost on the portable front. Many felt that IBM's new, uniquely architectured
Cell processor, which Sony is placing at the heart of the upcoming Playstation 3, would be the answer to Apple's dilemma. It was not to be.
When asked about about it, Steve Jobs indicated that Sony had tried to sell Apple on the Cell processor, but that he was disappointed with its design.
Jobs indicated that he "believes Cell will be even less effective than the PowerPC." It turns out he had a pretty good take on the situation.
AnandTech has recently published a story entitled "
Microsoft's Xbox 360 & Sony's PlayStation 3 - Examples of Poor CPU Performance." (The story was pulled shortly after its publication, apparently due to Anand's concern that it would lead to Microsoft tracing his anonymous insider, and as such the story link is to a Google Groups cache.) The article examines the PS3's Cell processor and the Xbox 360's Xenon processor—both PowerPC derivatives, and notes just how poorly these two units perform in real world tests.
In the end, you get what you pay for, and with such a small core, it's no surprise that performance isn't anywhere near the Athlon 64 or Pentium 4 class. The Cell processor doesn't get off the hook just because it only uses a single one of these horribly slow cores; the SPE array ends up being fairly useless in the majority of situations, making it little more than a waste of die space.
The most ironic bit of it all is that according to developers, if either manufacturer had decided to use an Athlon 64 or a Pentium D in their next-gen console, they would be significantly ahead of the competition in terms of CPU performance.
Clearly in real world usage, the Cell has nothing on the current G5. A move to the Cell would have been a step in the wrong direction. As it stands now with the move to Intel, the processor that will be sitting at the core of future Macs has
a bright future, indeed.
Slashdot's coverage of this story has an interesting user comments thread.