Read speed of Pioneer A06 compared to BTC DVD-ROM drive

I just got a Pioneer A06 writer & a 250GB disk

I used DVD Decrypter to rip a DVD to the new hard disk from the A06 drive &
my old BTC DVD-ROM (DVD16X-OEM316B) drive I picked up at Fry's a few years
ago.

The A06 ripped at a constant 2.1x speed. took about 48 mins.
BTC started at about 2.0x, then the speed increased to the max of 10.4x,
averaging at about 6.8x, finished the rip in less than 15mins.

The BTC drive is connected to the MB's 2nd IDE channel (Ultra DMA 100) as
the master drive operating at DMA mode 2.
The A06 drive is connected to a separate Promise Ultra 100 controller (2nd
IDE channel, master)
The 250GB hard disk is connected to the same controller (1st IDE channel,
master)

I was surprised & disappointed a bit, since I expected the A06 to match or
exceed the BTC drive in the ripping speed.

BTW, I compared the images on the hard disk, they were identical (all 8GB)
so it wasn't like the BTC drive was dropping data.

Can anyone explain why the A06 is so slow at ripping?

Maybe I need to go to PromiseTech site to get a latest BIOS/driver for
WinXP?

Thanks,

yuki