First, you should know not to double-post.
Second, I worked out 24 pipelines from your figures and NVidia's own claims. I have subsequenty tried to find somewhere that confirms this, and failed so far. So while I may not have the data to back me up, neither do you for your claim of 16.
Thirdly, you can't really compare Cell and Athlon: they're totally different chips, intended for different applications.
At the end of the day, there's very few figures you can use to truly measure performance. For GPUs, the main one is FLOPS (floating-point ops per second). For CPUs, it's CPI (clocks per instruction) coupled with clock speed.
I won't carry on until I have the figures to hand. I recommend you do the same