Parallel vs Serial speed

[blu at vl.com (Tom Metro)]

markw at mohawksoft.com wrote:
> The drives I am testing are Western Digital WD2500JS and WD2500JB,
> which are identical except for the interface, and the SATA drives are
> more than 10% faster, and since the same computer was used and exact
> same drive mechanics are involved, and writing directly to the
> device, one has to assume that the different transfer characteristics
> lead to that.

There are other variables to consider. The SATA drive is no doubt 
attached via a different host controller chip, which might have a more 
efficient internal design that has nothing to do with the fact that it 
is SATA. In addition, that host controller might be attached to the CPU 
differently - passing through more or fewer PCI bridges. And lastly, the 
device driver, which I believe is different between PATA and SATA under 
Linux, might introduce differences in performance.

At least the good news is that the new style interfaces isn't 10% 
slower. :-)

  -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/

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