You should expect to see similar results with an equivalent PC...
-600 MHz PIII with 384 MB RAM (133 FSB) and WXP Pro SP1. All non-essential services OFF. Zone Alarm Pro firewall running in the background.
-System comes with 384 MB RAM. 229 MB of RAM still available for use during rip/write session. CloneDVD 220.127.116.11 pulls 23 MB. AnyDVD 18.104.22.168 pulls 5 MB.
-NEC 3500A with FW 2.18, bitsetting tool, riplock removed. 12X write. Yuden000 T02 8X Fuji media from Best Buy. Average CPU load is 70%. Write time is 8:09 including disc finalization.
-DVD is The Mask of Zorro. Main 137 min title with English AC 3/6 audio. 100% video quality. One DVD+R disc bitset to DVD ROM. Rip/transcoding time is 14:31. Average CPU load while ripping is 95%.
Total processing time is 22:40. Nero DVD Speed Test looks good. No playback issue with stand alone players. I normally rip at 4X (+7 min to the write time.