clonehdd followup

paul beard paulbeard at
Fri Jan 17 21:22:39 UTC 2014

On Fri, Jan 17, 2014 at 1:17 PM, Kevin Oberman <rkoberman at> wrote:

> Remember that 1.5GB/s is the speed supported by the electronics and the
> cache.  It is not the speed that the disk actually reads or writes from/to
> the platters. When cloning, very little of the data is in cache, so you are
> generally limited by seek times (should be minimal if the code is well
> done) and rotational speed. The really then boils down to transfer speeds
> are going ot be close to what is possible with the rotational speed.

Yeah, I knew 1.5G was our old friend, the theoretical maximum, or his
cousin, the optimal transfer rate. I was hoping for something better than

I'm sure there are any number of factors that are slowing things down. It
seemed like incorporating the larger blocks/boundary alignment might help.
I'm testing it now and I'm not sure I'm seeing it.

Paul Beard /

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