Not always, not exactly anyway. If you look at the 360 hardware it changed a lot over its life span and so did the PS2, by the end of both consoles life cycle the main CPU had shrank in die size several times and in the final revisions (PS2 slim & XBox 360 S) they had crammed their main and graphics processors into a kind of APU. The 360s Xenon CPU, its Xenos GPU & and the eDram from the Xenos chip where crammed into the XCGPU APU.DoPo said:Because it is the same hardware.
Functionally it was the same and gave similar performance at a greatly reduced power consumption and consequently heat output but in a technical sense it was a different set of hardware than the first 360s shipped with.