AD-7240S: SLOOOOW burn speed in Windows 7 eSATA enclosure



OK, here’s the scoop.

Sony Optiarc AD-7240S drive installed in a Vantec NST-530SU external enclosure using the eSATA connector, connected to HP laptop using Silicon Image SiL 3512 SATALink Cardbus controller.

Working under Windows XP with SP-3 everything is great, I get nice burn speeds, etc. (see attached).

Under a fresh, clean build of Windows 7 it will not exceed 2x burn speeds, and cannot keep the buffer full (under both CDSpeed & ImgBurn). Does anyone have any ideas why it would work wonderfully under XP and fail so miserably under Windows 7?

There is no DMA setting since it is using eSATA, and if I swap the hard drive in the laptop back to the XP operating system and boot it up, the cabling and hardware all function at full speed again. What is Windows 7 screwing up?

What am I missing here?

(This is how it performs under XP.)