OT 2nd posting pci ata card ??
Matthew Kuiken
matt.kuiken at verizon.net
Sun Apr 2 18:37:48 UTC 2006
Antony Gelberg wrote:
> Matthew Kuiken wrote:
>> I would highly recommend changing to a hardware RAID IDE card. The
>> downside to this is that I am not certain that you will not need to
>> re-install in the process of moving the drives from software RAID on
>> the MB to the hardware RAID on an add-in card. It may work, but I
>> would not hold my breath.
>>
>> The biggest benefit of hardware RAID will be in performance. You
>> will get the speed increase of being able to read from mirrored
>> disks, the reliability of having the two drive system, and the write
>> speeds won't have the overhead of software needing to perform two
>> separate writes, the hardware will take care of it. In all, if you
>> are adding a card, it is wise to move the RAID functionality into
>> hardware.
>
> Do you have any evidence to back this up? Most hardware RAID cards
> are just normal IDE cards with RAID drivers. Unless you spend obscene
> money. The overhead you speak of is negligible on every system I've
> used software RAID on.
>
I must apologize. I was basing my recommendation on my experiences with
SCSI RAID controllers ~12 years back. I assumed (bad idea, I know) that
since the ATA RAIDs are only 0, 1, or 0+1, that they were doing all the
necessary work in hardware. It really wouldn't be all that hard to do
so. I have done a lot of googling since sending my email, and have
learned otherwise. Because of this, I withdraw my recommendation for
the hardware RAID controller.
I even found this web site:
http://linux.org.mt/article/ata-raid
which, while old, adequately explains the trade-offs.
> Software RAID is better for most users as it's not dependent on any
> specific hardware, and is very configurable.
>
I agree. Thanks for setting me straight.
I now wonder, what, if anything, do the "ATA RAID" controllers do?
Other than re-building the disk through the controller BIOS after the
computer has crashed...
-Matt
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