Yes, consoles are better optimized, and data is offloaded onto the "synergistic processor", like the Cell or the Xbox's 3 core Xenon. But, I was strictly talking about raw performance of the GPU.
It's a bit harder for me to put up performance comparisons on the CPUs, since finding desktop equivalents is a bit of a problem.
I'll bit anyway, though, and suggest that the CPU performance is ALSO quite terrible.
The Cell processor in the PS3 has 241,000,000 transistors, and would be comparable to dual core Core2Duos, that racked in at around 291,000,000 transistors.
The average "modern" Quad core desktop CPU would have roughly a Billion transistors, and have undergone several architecture improvements since 2006. It's reasonable to assume that the Cell processor, would have less than 25% of the performance of a modern quad core CPU.
That also goes to show just how badly PC games are optimized. If you look at the numbers, it's pretty pathetic.