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VR accuracy. Those advantages could outweigh the down side of using up CPU
cycles inputting high bandwidth digital sound input over an ISA bus. The
point I was trying to make is, if you have a marginal CPU for NatSpk 3.0
with Best Match, a PCI sound card will allow the maximum number of CPU
cycles to go to NatSpk rather than using them to run the sound card.
Aren't there some good PCI sound cards? I have a Creative Labs / Ensoniq,
and it seems to work fine. (Although I haven't done any A/B comparison
tests.)
------------------------------------------------
At 09:50 PM 8/3/98 -0500, Holland St.John wrote:
>The Fiji is an ISA card, not PCI. I have not personally tried enough
>cards to say from experience whether PCI vs ISA makes a difference in VR
>use on typical machines, but reading the comments of many other users
>over the past year, particularly those who have used the various Turtle
>Beach cards with similar specs, but some PCI and some ISA, leads me to
>believe that the ISA vs PCI interface is not significant in VR accuracy.
>Other aspects of sound card design are far more important.
>
>Holland
>
>
>Jim Green wrote:
>>
>> There seems to be some confusion as to the merits of PCI vs. ISA sound
>> cards. Let me try to clarify this. Holland correctly states below that a
>> PCI card puts less load on your CPU than an ISA card. But he didn't say
>> why. (He also recommended a particular sound card as being good for NatSpk
>> because it has "flat frequency response and low noise in the input
>> circuits" which will make it easier for NatSpk to "decide" which words to
>> display. This is also very true.)
>>
>> The ISA bus was the original I/O bus released by IBM in 1985 with the "AT"
>> computer, with a 8 MHz 80286. It was good for I/O devices with very low
>> bandwidth such as slow printers, 300 baud modems, etc. The ISA bus is very
>> inefficient because most transfers to and from boards are "programmed I/O",
>> that is, a number of CPU cycles are required to transfer one byte from the
>> board to the CPU. With high bandwidth boards, such as digital sound input
>> cards, a significant fraction of the CPU can be consumed just inputting the
>> digitized sound to RAM. Also, digitized sound input can consume the whole
>> ISA bus bandwidth.
>>
>> The PCI bus is a recent Intel invention to overcome the bandwidth and CPU
>> intensive limitations of the ISA bus. It uses its own controller to unload
>> the CPU. Its bandwidth is very high and growing.
>>
>> If you have a very fast CPU (like a P-II 400) the amount of CPU stolen by
>> an ISA bus sound card will be a small fraction of available CPU cycles. As
>> your CPU gets slower, however, a larger and larger percentage of your CPU
>> will be consumed just inputting sound card data. Thus, contrary to what
>> was said here by another person, the slower your CPU, the more you will
>> benefit from a PCI sound card. Of course, this is "all other things being
>> equal", such as "frequency response and noise in the input circuits" as
>> Holland mentioned.
>>
>> ---------------------------------------
>> At 11:57 AM 8/3/98 -0500, Holland St.John wrote:
>> >Jim,
>> >
>> >The Fiji is a good card because of flat frequency response and low noise
>> >in the input circuits. There is no extra processing on the card that
>> >helps with recognition (there are lots of other extra chips that help
>> >with music production, mixing, etc, but those are irrelevant to VR).
>> >
>> >The Fiji will take some of the load off the CPU because the CPU has less
>> >noise to deal with, and therefore Nat and the CPU can "decide" easier
>> >which words to display.
>> >
>> >Holland
>> >
>> >
>> >Jim Walsh wrote:
>> >>
>> >> I am a bit confused. I just bought a PII 400 w/256 ECC SDRAM with a
>> >> 7,200 EIDE Seagate drive. I am considering buying the TB Fiji card. My
>> >> thinking is that the Fiji has a built in processor which may assist the
>> >> PII in some of the processing. Will the extra processor be a benefit?
>> >> What about the MMX instructions? Anyone have a clue?
>> >>
>> >> Robinson, Robert wrote:
>> >> >
>> >> > Our experience with both NS (not including BestMatch) and VV98 is that
>> you
>> >> > can run the software with a P 200 with 128MB RAM, but it is slow. A
>> Pentium
>> >> > II 400MHz with 256MB RAM does much better but CPU utilization during
>> speech
>> >> > processing is still "100%".
>> >> > Robert Robinson
>> >
>
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
James E. Green, Ph.D. # Jim@@RobotVision.com # 703-757-5140
Robot Vision Corporation
Computer Vision System Design & Implementation
9978 Blackberry Lane # 6 Mountain Laurel Ranch
Great Falls, VA 22066 # P. O. Box 569, Leakey, TX 78873
http://www.next-wave.com/jim.htm
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