[SunHELP] Setup hardisk[Q]

[Michael Vang]

> The U5 does support dual drives, although there are issues with the
onboard
> CMD IDE controller when using both channels...

>What are these issues?


I spoke with an engineer at CMD a month ago and he told me that the two
channels share certain resources and do not operate at full speed if
used simultaneously... It has something to do with DMA...

The newer PCIO646U2 fixes that problem, but the U5 has the older version
(PCIO646U)... Well, mine has the older version... I don't know about
newer U5s...

http://www.cmd.com/ApplicationNotes/0646UDesignTips.pdf

I don't really understand what he told me, and the PDF just confuses me
more... For now I am going to take his word for it... I'd love to put
another HD in my system, but not if it impacts performance severely...