The specs for the Cell Broadband Engine (jointly developed by IBM, Sony, and Toshiba) have been circulating for a while, and it is unlike any CPU I’ve ever seen. We’re used to the general-purpose world of the Pentium or the PowerPC. The Cell, however, is a "Heterogeneous Multi-Core" processor.
It has one main core (the PPE - Power Processor Element) and eight specialized cores (the SPEs - Synergistic Processor Elements). The PPE is a standard 64-bit PowerPC core, but the SPEs are the heavy lifters. They are SIMD (Single Instruction, Multiple Data) powerhouses, designed for the kind of intense floating-point math needed for physics, graphics, and video encoding.
This is a radical departure from the "just add more cache" approach of Intel and AMD. To get the most out of the Cell, you can't just write standard C code and hope for the best. You have to manually manage memory transfers between the main system RAM and the SPEs' tiny "Local Store" (256KB) using DMA (Direct Memory Access).
It’s hard. It’s incredibly hard to program. Game developers are already grumbling about the learning curve. But the theoretical performance is staggering—over 200 GFLOPS on a single chip. For comparison, the top-end Pentiums of today are struggling to hit 10.
Sony is betting the house on this for the PlayStation 3, but IBM sees it as the future of supercomputing and medical imaging. We’re seeing the first step toward "GPGPU" style computing, where we offload massive parallel tasks to specialized hardware.
Will it succeed? In the console space, definitely. In the general-purpose PC space? Probably not. The barrier to entry for developers is just too high. Most programmers want to write code, not manage DMA buffers. But for those who can master the Cell, they’ll have the power of a mini-supercomputer at their fingertips.
// Concept of an SPE DMA transfer
spu_write_out_mbox(DMA_TAG);
mfc_get(local_store_addr, system_mem_addr, size, DMA_TAG, 0, 0);
mfc_read_tag_status_all();
The Cell is a beast, but it’s a beast that requires a very skilled tamer.