- Messages sorted by: [ date ][ thread ][ subject ][ author ]
- Next message: Jim Green: "RE: P-II 400 disk activity"
- Previous message: Su: "Query from a co-worker"
- In reply to: L.C.Jackson@@psd.maff.gov.uk: "Re: Bring-up Word file"
- Next in thread: Patrick Henebry: "RE: Naturally Speaking macros and command/control"
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
>
- Next message: Jim Green: "RE: P-II 400 disk activity"
- Previous message: Su: "Query from a co-worker"
- In reply to: L.C.Jackson@@psd.maff.gov.uk: "Re: Bring-up Word file"
- Next in thread: Patrick Henebry: "RE: Naturally Speaking macros and command/control"
 |  |