On 2014-08-11 15:39, Blaicher, Christopher Y. wrote:
> I have not researched this, at all, so this is an educational question.
> 
> From your response to Barry it seems you are saying the Binder will write a 
> 32K block and then write a short block on a track?  
>
Yes (I have been told).

>If it is doing that, then how is that any better than a Half-track blocksize?  
>It is still two blocks per track, or are you saying the binder wastes the 
>remainder of the track?
> 
It does not waste the remainder of the track.  But if Binder needs to
write 32760 bytes, then:

o If BLKSIZE=32760, it will write 32760 bytes followed by an IBG.

o If BLKSIZE=27998, it will write 27998 bytes, an IBG, 4762 bytes,
  then an IBG.  One more interblock gap, and correspondingly less
  space for the next block.

The difference is tiny; I'll leave it to the Half-track advocates
to concoct a scenario where Half-track is superior.

And for PDSE, it scarcely matters.  Everything is written in 4KiB
pages.  (But does Binder know this and ignore the specified BLKSIZE?)

-- gil

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