Multi-core CPUs were still starting out to be fair, but they were definitely at least somewhat mainstream by the time of the 360/ps3. The 360 was tri-core, and was considered easier to develop for since all three of those cores shared resources. Meanwhile, the cell architecture is hard to develop for even by modern standards. As such, most games only made use of the PPE and left the SPE alone.
Multi-core CPUs were still starting out to be fair, but they were definitely at least somewhat mainstream by the time of the 360/ps3. The 360 was tri-core, and was considered easier to develop for since all three of those cores shared resources. Meanwhile, the cell architecture is hard to develop for even by modern standards. As such, most games only made use of the PPE and left the SPE alone.