We first started talking about the Freescale PowerPC G4 7448 CPU way back in 2004, and fully expected to see them in the wild by 2005.
Boy were we ever wrong. It is now almost 3 years later and only now are we finally seeing those 7448 upgrade cards available for purchase. The max speed is 2.0 GHz for single-CPU cards, and up to 1.8 GHz for dual-CPU cards. Unfortunately, no Cube-specific upgrade cards are offered.
As expected, these 90 nm chips are cooler running, and thanks to their 1 MB L2 cache (double that of the 7447A) and improved Altivec execution, they are also much faster clock-for-clock compared to previous G4 chips. xlr8yourmac has the first review.
While a huge improvement over previous G4s, it's too little, too late. The US$679 dual 1.8 upgrade card is still significantly slower overall than even the low end $599 1.66 GHz Core Duo Mac mini.