On Thu, Apr 20, 2000 at 04:19:59PM -0400, rpjday wrote:
>
> On Thu, 20 Apr 2000, Juan Martinez wrote:
>
> > I've read every message in this thread and have one question.
> >
> > Does it matter what block size is used with the dd command? I
> > know you should use the same size when writing the floppy that
> > you used when creating the image.
>
> nope, not necessary. generally, the larger the block size, the
> more efficient, but i recall doing some benchmark testing a while
> back and once you go above a few K for a blocksize, it doesn't
> really matter. just don't leave it at the default blocksize of
> 512 bytes -- really slows things down.
> >
> > I'd probably use 1440k because it's the size of the floppy but
> > I'd still like to know if it matters.
I haven't tried this on Linux, but I have done testing on other
systems (more than 1) a few years ago, and in those tests I found
that the best throughput was with a blocksize equal to two tracks
for both sides of the diskette. I.e., for a high density 3.5" floppy,
a blocksize of 36 sectors was good, 72 was somewhat better. Larger
than that didn't make any real difference. 18 wasn't bad. The default
of many programs of 20 is, OTOH, **horrid**. I don't know how to test
this, but my guess has been that it has to do with disk rotation
latency.
Fred
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---- Fred Smith -- [EMAIL PROTECTED] ----------------------------
"For him who is able to keep you from falling and to present you before his
glorious presence without fault and with great joy--to the only God our Savior
be glory, majesty, power and authority, through Jesus Christ our Lord, before
all ages, now and forevermore! Amen."
----------------------------- Jude 1:24,25 (niv) -----------------------------
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