Dual-channel PCI IDE card?

Previously Mike Ruskai <BUTthannydI RemoveThis @dontearthlinklike.netspam> wrote:
> On or about 10 May 2008 15:48:01 GMT did Arno Wagner <me RemoveThis @privacy.net> dribble
> thusly:

>>Previously Mike Ruskai <BUTthannydI RemoveThis @dontearthlinklike.netspam> wrote:
>>> On or about 9 May 2008 09:04:00 GMT did Arno Wagner <me RemoveThis @privacy.net> dribble
>>> thusly:
>>
>>>>Seriously, a software RAID1 load is massively slowed down when
>>>>both drives are on one IDE channel. With the Promise cards,
>>>>it is not when the two drives are on two channels. With this
>>>>my statement becomes relevant to the OP's question.
>>
>>> Not necessarily. If the card is handling the RAID, then it's
>>> equivalent to only one drive. The card may be easily able to
>>> read/write from/to both drives independently, but it's only using
>>> the bus for one logical drive.
>>
>>... "software RAID" ...

> Ambiguous. Software RAID 1 on a single IDE channel, or some unspecified type
> of RAID 1 on a RAID adapter. I saw it as a comparison between what's
> available with and without said RAID adapter. Hence, "Not necessarily", as
> opposed to "no, you're wrong, blah blah".

Since I never mentioned RAID adapters, what do you think
I meant?

>>> If you really want to know whether it's relevant to my original
>>> question (independent DVD drive use), you'd have to confirm that a
>>> software RAID0 array on the card works, since then both hard drives
>>> are transferring data on the bus.
>>
>>> As it happens, the Promise cards have a reputation for not
>>> supporting ATAPI properly, so it doesn't much matter whether the
>>> channels are truly independant, as far as I'm concerned.
>>
>>Some people claim that is a myth. I would'nt know.

> When several different people who have bought the card post about the same
> kind of problem, I give it some weight. It may be that the card does in fact
> share bus communication between the channels, so that someone using a hard
> drive on one channel and a DVD burner on the other gets poor results when
> trying to write to the latter from the former. Either way, if several people
> complain about DVD drives not working, it's not exactly a good bet for me to
> buy it for nothing but DVD drives.

> In any case, I have since purchased an Asus DRW-2014L1T SATA drive, which so
> far seems to be working just fine. I can't say I understand the label of
> "20x" DVD write speed, when it never gets above 16x during a full disc write
> (on Verbatim 16x DVD+R MCC media).

That is, I bleive, called design for marketing. There will be
one specific media it can do 20x with, but only the one....

> And strangely enough, it actually slows down near the end, while
> all the other burners I've had speed up near the end, when the
> linear speed of the media under the laser is at max.

Maybe it has problems with vibration. That is wors towards the end.

> But at least now I can use three drives at a time at full speed.

Good. So I see your problem is solved.

Arno