Hi...I'm trying to setup on XP Home an LG Electronics SATA GH22NS30
DVD-writer on an older Intel D845PEBT2 motherboard (ICH4 core) with a
Silicon Image Si3112 SATA controller. It 'should' work but something
is wrong.

The drive reads both DVD and CD data disks, but a bit slow (8 MB/s). I
can't write either type at all. Using Nero 7, or another writer, it
stalls consistently about 10% into the write, even in simulate mode.
Both the Silicon Image configuration utility and Nero report the drive
in PIO4 mode.

I have been able to boot from the writer by configuring it to do that
in BIOS, but there's nothing else in BIOS related to SATA except a
means to enable RAID, which I don't want. I returned the drive to the
retailer and they supposedly tested it. They claim it's working fine.

It seems the PIO4 mode is way too slow but I have no means to manually
switch to UDMA mode. There is a feature in the SI config utility for
switching between modes, but all it does is write an entry to the
registry which is ignored. There is nothing in Device Manager for
switching modes.

I have a hunch it may have something to do with Microsoft. They check
for CRC errors, and if found, they drop the transfer rate back one
level at a time till a suitable level is found. I don't know where
they do that, but if that is the case, it's supposed to revert to UDMA
mode if the driver is deleted and re-installed. It doesn't, unless
it's doing it so fast I'm missing it.

I'm out of ideas. I downloaded the WDK and may try to trace the code
using a debugger. Before doing that, I'm hoping someone will know
something.