Hi,

I was trying to get my daughter's PC ready for her going back to college,
and ran across a strange problem. I was able to get around it, but am still
puzzled by it, so I thought someone here might have some idea of what was
going on.

The PC had:

MB: Asus A7V8X-X
CPU: Duron 850
RAM: 1x512MB PC2700
HD: 1x60GB (don't remember brand)
DVD: generic 10X
CD/RW: TDK 32X (I think)
OS: Windows XP Home SP1

Originally, we had the HD on primary master, the DVD on secondary master and
CD/RW on secondary slave, and I think it was working. A couple of months
ago, before summer, she was not able to burn CDs. A couple of weeks ago, my
son replaced the TDK CD/RW with his Plexwriter 40X, but he didn't do any
testing, and this is what I "inherited".

IDE drivers were the generic MS/Via drivers that install with Windows XP
Home.

When I first started looking at it, she could burn CDs, but got high CPU
usage and you could see the buffer during the burn going really low.

I first checked DMA, and the CDRW was showing "PIO" even though "DMA if
possible" was selected. So I tried the 'set to PIO, then set to DMA' trick,
and it kept saying PIO. After doing some searching, I found a post saying
to set it to "DMA if possible", then delete the IDE in Device Manager, and
reboot. I did that, and sure enough, after the reboot, it showed "UDMA 2".

But the problem was that I couldn't burn at all using Nero. It kept giving
me a "device fault" error. Tried switching IDE cables, and switching
position of the DVD and IDE on the IDE cable (both drives had cable select),
to no avail.

Just by accident, I was testing with just the CD/RW on the IDE cable, and to
my surprise, it was working!!

I put the DVD back on the IDE cable (as slave), and after reboot, Device
manager showed the CD/RW as "PIO" again.

Mind you, both the DVD and CD/RW were listed as "UDMA2" by the BIOS display
through all of this.

Anyway, by this time, it was about 04:00, and I just happened to have a Siig
Ultra ATA 100 PCI card extra. I put the CD/RW as secondary master, and the
DVD on one of the ports on the Siig card.

When I rebooted, everything was working perfectly. DVD playing was fine,
and I could burn CDs with low CPU usage.

My conclusion is that somehow, the DVD and the CD/RW were interfering with
each other when they were on the same IDE channel. But, I know that the
CD/RW was good, because it was working in my son's machine before he moved
it over.

I guess I'm happy that it's working now, but I'm still puzzled by why I
couldn't get both the DVD and CD/RW to UDMA2 when on the same IDE...

I suppose the one possibility that I didn't test was using a different DVD
drive, since I don't have a spare.

Jim