Re: [LAU] hardware - Intel CPUs

On Thursday 17 April 2014 06:09:56 david did opine:

> On 04/16/2014 02:54 AM, Gene Heskett wrote:
> > On Wednesday 16 April 2014 08:44:15 david did opine:
> >> On 04/15/2014 03:17 AM, Len Ovens wrote:
> >>> On Tue, 15 Apr 2014, James Mckernon wrote:
> >>>> On Mon, Apr 14, 2014 at 2:06 AM, Len Ovens <len@email-addr-hidden>
wrote:
> >>>> I would realy like to stay away from having to use a USB or
> >>>> FW audio IF. In fact I would like to be able to continue to
> >>>> use my delta 66 for as long as I can before I spend more
> >>>> money :) The
> >>>>
> >>>> Thanks for the useful info in your post. Just to be clear on this
> >>>> part: are
> >>>> you saying you don't want to switch to USB/FW solely because you
> >>>> want to keep using your delta 66, or because you have some
> >>>> definite preference for
> >>>> PCIe over USB/FW devices? If the latter, I wonder why?
> >>>
> >>> USB in audio is limited. Getting clear USB ports interrupt wise is
> >>> not easy. Audio can not be on a hub or share it's usb with anything
> >>> else, but many new MB have no mouse or kb port so the USB is
> >>> already being used for that much. The real reason though, is
> >>> latency. With the pci the latency can be 1/4 what it can be in USB
> >>> or FW. That is the lowest seeting jack for USB or FW is 64/2, but I
> >>> can run the d66 at 16/2 with no problem on a well tuned system.
> >>> This does make a difference for live work. I know that 64/2 seems
> >>> like very good latency (it is) but remember that the card then adds
> >>> another ms in each direction as well as the stage distances on top
> >>> of that. That is the time it takes the sound to reach my ear after
> >>> going through the computer as a processor and then through the air
> >>> to my ear. Maybe that is still not worth worrying about... but even
> >>> with 30 feet of cord and no digital delay, I can hear the delay
> >>> from my playing to the sound reaching my ear.
> >>
> >> Interesting. What is the difference between speed of sound in air and
> >> the speed of electricity through a cable?
> >
> > Sound is nominally 720 miles per hour. Rather leisurely IOW.
> > A perfect cable is C speed, 258 times faster. But cable (coaxial)
> > actually range in speeds between 66% of C for home usable cables, to
> > around 98% of C for 9" diameter high power broadcast stuff, C being
> > 186,272 miles per second in a vacuum. Thats 298,035.2 kilometers per
> > second for the metric folks here.
>
> Then running your sound from stage to backhouse sound board back to
> stage and hearing it through headphones would give no latency at all.

For an analogue board, small fraction of a millisecond, for a digital
board, anybodies guess. A/D and D/A's are essentially pretty quick, but I'd
still put most digital boards above a millisecond.

Cheers, Gene

-- 
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