[rescue] 36G SCA drives still looking
nate at portents.com
Sat Mar 5 14:55:32 CST 2005
On Sat, 5 Mar 2005, Charles Shannon Hendrix wrote:
> What I don't understand is why the industry wasted so much time IDE.
> SCSI was better, and at the same quantities, the price should be about
> the same.
SCSI never sold in the same quantities as IDE, which is why IDE was always
less expensive. Also, for systems with 1-2 drives, a single IDE
controller was less expensive than SCSI. Especially when you factor in
that IDE was only PIO and didn't even have DMA until relatively late in
> I don't see any reason for IDE to have ever existed.
It was simpler and therefore cheaper and people didn't care.
> Also, since IDE drives have to have a controller on each drive,
> shouldn't they technically cost more than an identical SCSI drive?
Slave/Master was a simple (and stupid) way of making IDE even less
expensive. If the majority of computers sold actually had 5-7 storage
devices per system, SCSI absolutely would have been cheaper, but computers
shipped with 1-2 storage devices per system for a long time.
> Or do the extra capabilities of SCSI mean that their PCB is just as
DMA, scatter-gather, device disconnect, and bus mastering were all common
technologies with Ultra-Wide SCSI when IDE was still crawling on the
ground in PIO mode. SCSI was more expensive to develop and produce
(especially at the controller level) for a long time, cabling was more
expensive because it had to handle higher speeds and greater quality and
you had to deal with things like termination, and most people didn't know
any better or care at the consumer level.
Now we have SATA, which takes a subset of SCSI (ATAPI) and marries it to
fiber channel packet technology, and is now inheriting other SCSI
technologies like NCQ. Unforunately there is a problem with a few
different standards bodies for SATA, resulting in lack of industry
cohesion. And then folks like NVIDIA go and disable SATA-II capabilities
in the nForce 4 chipset, but have it enabled in the nForce 4 Ultra, for
reasons of product differentiation (and good luck trying to find a PCI or
PCI-Express SATA-II card right now). Also, NVIDIA's implimentation does
not scale as it should in terms of NCQ performance, while Intel's chipset
implimentation does. Intel sees SATA-II as a way to push chipset sales,
as a value-add for motherboard integrators, as much as any storage
technology on it's own. Intel doesn't hesitate to have a PCI-Express SCSI
RAID storage card, but doesn't carry a single PCI-Express SATA card.
Ah, the games companies play...
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