Dvd Tower Duplicators?

I was doing a google seach yesterday for NEC 3540 or 3550 that will be coming out in the usa soon and was given a link for several dvd duplicating machine sites as well. So I clicked on it and discovered that these 4-8 drives machine(989 dollars and up) use the same type of drives that consumers install in their pc's except that they are house in a special tower, and have more buffer memory, and have some type of controller that would I guess controll all the drives.

So I was wondering what exactly is this so called controller that would allow all these drives to run at 12X or higher speeds when If I install two 16x dual layer drives in my computer and burn at 8x it will use up almost 90% of my cpu cycle.

Is it possible for me to install more than two or more drives in my pc and use less than %50 cpu cycle or build my own dvd duplicating machine for a hell of a lot less than what these sites are selling for. This question is not for piracy or duplicating disks on a large scale. It is just a question that I am curious about.