Kibo informs me that Ken Weitzel stated that:



Matt Austern wrote:

Chris Cox writes:


I've tried. Their engineer insists that it's 30x faster to work with
15 bit quantities than 16 bit ones.

Which is correct (for 0..32768 representation versus 0..65535
representation).


Perhaps this is offtopic, and perhaps you can't answer it without
revealing proprietary information, but can you explain why 15-bit
computation should be so much faster than 16-bit? (If there's a
publication somewhere you could point me to, that would be great.)
I've thought about this for a few minutes, I haven't been able to
think of an obvious reason, and now I'm curious.

Feel free to email me if you think this wouldn't be interesting to
anyone else.


Hi Matt...

Nor can I see even the slightest difference. None at all.

So - I suspect that we're looking at it from the wrong
end. Suspect it's the a/d converter that could be the
bottleneck?

Unluss I've totally misunderstood John's description, none of this data
has been anywhere near an A2D converter.

8 bits are common; 15 bit's are common. 18 bit
are available but seldom used. Never heard of 16.
Maybe that's it?

Nope. (BTW, 16 bits is standard for audio work, including CDs, & 12 bits
is standard for DSLRs.)

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