Re: [Sheflug] RAID Cards

[Alex Hudson <home [at] xxxxxxxxxxxxxx>]

On Wed, 2004-04-14 at 12:16, Darrell Blake wrote:
> So what is the point of SATA then? Is it just that it can run at 
> 10000rpm? Can't PATA do this?

The disk speed (10krpm) is nothing to do with the interface.

SATA should scale higher than PATA in terms of wirespeed, because serial
is much easier to time than parallel. It should also be simpler to
implement. It works on lower voltages, and is more intelligent - no
jumpers, no cable select, etc. The main issue is probably airflow and
cooling - today's PCs need all the airflow they can get. In tomorrow's
BTX systems (if they ever arrive), the thick PATA cables would stop the
work of the mammoth fan sitting atop the 1Kg heatsink.

>From http://www.serialata.org/about/index.shtml :
        
        Hard disk data rates don't seem to be pushing the limits of
        current ATA66 technology. Why is Serial ATA being planned now?
        
        Serial ATA is an evolutionary replacement for the Parallel ATA
        physical storage interface and will allow future enhancements to
        the computing platform. Specifically, the thinner Serial ATA
        cable addresses OEM's concerns regarding airflow around the
        Parallel ATA cable, and enables design of smaller PC chassis, as
        well as silicon vendors concerns regarding 5 volt tolerance
        support in future designs.

(Note "isn't pushing [..] ATA66" - they are admitting the actual
interface speed is worthless) So, it doesn't give you anything now, but
should be easier to extent in the future.

Cheers,

Alex.

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