Do you mean "rip" as in pull it off the DVD or "rip" as in convert it to another format? Ripping is not CPU intensive. And I can believe you can convert a 65 minute DVD to another format in 15 minutes. They had achieved about 1:1 years ago with about 1.3 GHz processors.
However, that was old formats at DVD resolution that don't take much CPU power for encoding. MPEG4 H.264 is about the best CODEC out there today for quality at any bit rate, but it is also notoriously processor intensive compared to the old codecs. You need a pretty blazing multi-core (or multi-processor, or both) machine to get 1/4 time processing of DVD video with the encoding bells & whistles turned on. I'd love to see the computer that can do that with HD.
.BUP -> MPEG-2.