IDE connections

Sorry in advance for my ignorance, but this is puzzling me!

My 1GHz Athlon system is based on an Asus A7V (no other suffix) motherboard, which has a total of four IDE connectors on it - an ATA 100 primary and secondary run by an onboard Promise controller chip and a ATA 66 primary and secondary which do not use this.

My system was supplied with its hard drive on the Promise ATA 100 primary, a CD-RW drive as master on the onboard ATA 66 secondary, and Pioneer DVD-116 DVD-ROM drive as the slave on this ATA 66 primary. When upgrading the original CD-RW drive for a faster model, it was suggested that it would be beneficial to split the two optical drives to avoid bottlenecks in on-the-fly burning.

Therefore, I moved the Pioneer DVD-ROM to the onboard ATA 66 primary as master, leaving the CD-RW as master on the onboard ATA 66 secondary. The new, additional IDE cable happens to be an 80-strand one, which I thought might be beneficial as I had heard the Pioneer is ATA 66 compatible, and indeed the BIOS recognised this and set it to ATA 66.

Now my questions: to my surprise, making this change to the setup disabled the capability for digital audio output on both drives, which had hitherto been present. Though I don’t know why it happened, I could perhaps understand the DVD losing it, since it was the one using a new port and cable, but why the CD-RW also, when it is on the original (different) IDE connector and cable? Both were attached to the end connector of their respective IDE cables. The Pioneer’s audio quality in CDSpeed also dropped from 10 to 1! (Though it still had the “perfect” box ticked). Strangely, having this setup also showed an oddity in the data transfer rate for the Pioneer, which now started at a very low speed (7x) and climbed steeply for a while until it became normal (and never any better than the previous setup).
This, combined with the fact that my CD-RW drive is too far from the soundcard (yes, I know I could move them if I was more confident!) for an analogue audio cable to reach, caused me to return them to the original setup on one 40-strand cable, and everything went back to normal - digital output on both drives, normal quality scores and transfer curves. Any clues about why this happens, please?

A final question: my Pioneer DVD-116 only seems able to extract audio at a maximum of 16x, whatever the setup. Is this normal for this drive? DMA is enabled and on the original cable layout it operates at ATA 33.

Thanks,

H

my Pioneer DVD-116 only seems able to extract audio at a maximum of 16x, whatever the setup. Is this normal for this drive?

Yes, this is normal for many drives.

it was suggested that it would be beneficial to split the two optical drives to avoid bottlenecks in on-the-fly burning.

There is no “best” IDE configuration for CD/DVD drives. You must use whatever works well on your board. IDE drivers also play a big part is realizing high speeds. I see 48x CD-copy speeds on my own system when I have both CD drives on the same channel, in fact it makes no difference where they are. since you have the extra channels, it would seem logical to place the optical drives on their own channels, each as master. You may need to upgrade your cables. And make sure that ALL drives are running at DMA status in BIOS.