Pro1 & Dimage A2 RAW file size difference?

Is there any reason why the image sizes for the following cameras are different?

JPEG max resolution and size:
Canon Powershot Pro1: 3436KB
Minolta Dimage A2: 7923KB

RAW:
Canon Powershot Pro1: 9020KB
Minolta Dimage A2: 11892KB

They are both 8MP with 2/3" CCD. I image the the JPEG size differences would be due to varing amounts of compression, but why such a difference in RAW?

Thanks,
Blademan

Blademan-
RAW files are all proprietary. They're all different so they won't be the same size. I've compared Canon's RAW with Nikon NEF files before and the sizes were very different. Unless the manufacturers standardize their RAW formats, they'll remain different.