UDMA66 Hard disk and UDMA33 CD-ROM!

[RobUK]

I got a new hard disk the other day, Seagate Barracuda ATA II 30.6Gb 7,200 RPM. Its set up on the UDMA66 cable on it own, primary master. I also have a UDMA33 CD-ROM and a Mode 4 CD-R on the secondary IDE. Sometimes get Underbuffer run errors with the CD-ROM and Writer on the same IDE, if i'm backing up.

If i put the UDMA33 CD-ROM on Primary slave would the UDMA66 hard drives transfer rate be dropped to UDMA33 speed to match the CD-ROM???

I want to be able to get the best out of the hard drive even if the CD-ROM and writer have to be put on the same ide!

Any advice??

Thanx RobUK

[Fingers]

Here's a similar thread. If ATA/33 and ATA/66 on the same channel, what speeds do they run at? (http://www.sysopt.com/forum/Forum1/HTML/012642.html)

This quote was taken from the Seagate FAQ: (http://www.seagate.com/support/kb/disc/ultra_ata_66.html#8) Can I mix Ultra ATA/33 and Ultra ATA/66 drives on the same cable?

Yes, a legacy ATA specification drive can coexist with an Ultra ATA/66 drive, and both devices can attain their maximum performance. However, for the Ultra ATA/66 device to attain Ultra DMA 4 mode, an Ultra ATA/66 capable cable is required.

Some members seem to have found this not to be the case for them however.

I wouldn't worry about it though, this review indicates that ATA-66 doesn't offer any real world advantages over ATA-33 anyway.
Ata-66 vs Ata-33 (http://www.hwupgrade.com/hd/ata66_vs_ata33/)

If you're interested in knowing for sure if you're getting ATA-66, use SiSoft Sandra to benchmark your hard drive while it's on it's own channel, then move the CD-Rom to that channel and bench it again.



[This message has been edited by Fingers (edited 04-14-2001).]