Edge magazine has completed a huge 10 page reveal in their latest issue which states that the Xbox 360 version of Rage - which uses id's new Tech 5 engine - matches the 60fps framerate of the PC version, while PS3 runs at just "20-30fps".
John Carmack, the acclaimed game developer behind id softwares Rage, is quoted as saying
The PS3 lags a little bit behind in terms of getting the performance out of it,the rasteriser is just a little bit slower - no two ways about that.
The RSX is slower than what we have in the 360. The CPU is about the same, but the 360 makes it easier to split things off, and that's what a lot of the work has been, splitting it all into jobs on the PS3.
Whether or not this is proper representation of his words and when these were said remains to be seen. I personally am not in the business of believing Edge Magazine in anything they claim without proper facts but this is the news that is going around the net at this time.
I am reserving my opinion on the issue but I would like to point out that if this is in fact true, then Carmack would have reason to be ashamed. There are many examples of multiplatform games on the PS3 performing on par with their 360 counterparts and for his game to fail to do so is not in his best interest.