I have two different PCs. One, a P4 2.8E, 512MB RAM, SIS Chipset, with a Plextor PX-708, Sony 1633 DVD-ROM (Liteon 167T) and WD250GB hard drive.

The second, a P4 3.0E, 512MB Dual Channel, i875 Chipset, with Plextor PX-712A and Sony 1633. Western Digital 120GB and WD160GB hard drives. One hard drive is connected via SATA.

I record movies and TV shows from my Tivo with my Pioneer DVR-225 DVD-R/W recorder. I then rip the DVD into TMPGEnc Express to be converted from 544x480 (Pioneer feature for DVDs with 2 or more hours of video) to 720 x 480. I just ripped a DVD a few minutes ago and noticed that it ripped 2 hours of video in about 5 mins.

I thought it was a bit strange since I ripped a DVD with my PC with SiS chipset Wednesday night and it took almost an hour. So, I put the same DVD that I ripped in 5 minutes today on the 875 PC into the SiS PC and there's a huge difference in rip time, 5 minutes versus one hour.

Can anyone explain why there is such a huge difference in rip times between the two drives. Does the PX-712A read that much faster than a PX-708A? Or, is there something wrong in my SiS system that's causing such a disparity?

Both systems are configured almost identically. Media is Memorex DVD-RW, DVD Identifier Reports it as Ritek RITEKW01