Jim Lux wrote:
At 01:04 PM 8/20/2005, Ken N9VV wrote:
o Flex tutorial on how it is that a Pentium IV has
enough horsepower to perform all the DSP arithmetic when
an Orion from Ten-Tec has two very fast dedicated DSP
chips and the IC-7800 has four.
The Orion is really two receivers in one box. While the SHARC is a fast
floating point DSP (and actually available in a radiation tolerant version
if you care), what speed does it run at?
Remember that the SDR1K DSP is essentially an audio application. It runs
at audio bandwidths. Strictly in terms of number crunching, it's not all
that much more heavyweight, maybe a factor of 4 to 8, than a typical
soundcard digital program. All the RF stuff is done by the hardware.
On the other hand, the Orion and 7800 DSPs run at IF, don't they? That's
a lot more samples per second. A Pentium or PowerPC would be quite
adequate for that job, but they wouldn't have headroom for much else,
they need more glue, and they're wattage pigs.
The SDR1K represents a very sensible division of labor between hardware
and software, given the current state of general-purpose hardware at
this point in time.
73
Frank
AB2KT
