Fun bit of history there. The CELL processor was a project kicked off by Sony, IBM, and Toshiba in 2000. It was a "forward"-looking heterogeneous computing design, in which one kinda-sorta-general-purpose "PPE" core manages a number of extraordinarily computationally-focused "SPE" cores. You might notice that Xenon's cores are also sometimes referred to as "PPEs"; this is because, when Microsoft approached IBM years later with their requirements for a next-gen console CPU, IBM decided to use the CELL's PPE as a basis for the cores in a 3-core design for the 360. (Not everyone at Sony was happy that this occurred, lol.)

Anyway, the PS3's CELL has one PPE and seven SPEs (the die has eight, with one shut off for redundancy). The PPE is similar to a Xenon core, with 32-bit instructions and 64-bit data registers, plus some 128-bit SIMD registers. The SPEs also use 32-bit instructions, but all data registers are 128-bit; scalar executions can only handle up to 64-bit precision, and the idea of the large data registers is SIMD.