By busy I mean at 100% cpu and physical memory for 8 or 9 hours. :-)
Thing1 and I built new computers last year. Nothing fancy - Athlon 64 3000+ with a gigabyte of RAM. Thing1 built his for games where mine was meant for video work. I've been taking my 8mm and miniDV tapes and making DVDs out of them. Generating that DVD takes an hour or so. 8 hours would be a challenge.
Started by recording 24 to one of my PCs using a Hauppauge PVR250 card in near DVD quality. Edit the resulting MPEG using Adobe Premiere Elements to remove the commericals and write a DVD quality MPEG. That takes about 45 minutes but it doesn't chew up the machine. Repeat for all 4 episodes broadcast this year.
Now fire up Premiere Elements again and add all four episodes as video sources. Mark each element with a scene tag and then create a DVD menu. Now set Premiere to create a 8.5GB DVD image on disk. Adjust quality as necessary. Hit the start button and let it go. Within a few minutes CPU was at 100% utilized and the 1GB of RAM that the machine has was completely used.
When I went to bed 5 hours later the progress bar was at 65%. According to the file modification times writing the DVD image took 8.5 hours. Busy, busy, busy.
Now to buy some dual layer media.