[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

*Subject*: RE: [linrad] FFT performance*From*:w3sz@xxxxxxxxxxxxxxxx>*Date*: Thu, 14 Nov 2002 23:57:17 -0500

Hi, Edson! A similar thing happened to me a long time ago on my Pentium Pro 200. I don't remember the details (more than 2 years ago, I think) but I think the following: Three things: 1. Does the same thing happen when you type "A" for weak signal Cw or "D" for SSB as it does when you type "F"? 2. There may be a parameter file there that is causing problems. Look for par_userint in the 'lir' directory where linrad is. It may be that the adspeed is set to 48000 or something that overtaxes your cpu (though it shouldn't). I attached par_userint listing below to show you what my parameters are. But this may be too much for your machine. Try setting the AD speed to 11025 or something even lower. You can edit this file on your machine with a text editor. vga mode [12] font scale [1] mouse speed [100] input mode [7] rx channels [2] ad channels [4] ad speed [96000] ad device no [0] ad device mode [0] ad frag [0] da device no [7] min da speed [5000] max da speed [48000] max da channels [2] max da bytes [2] min da channels [1] min da bytes [1] check [2220024] My par_wcw file (for mode 'a') is: First FFT bandwidth (Hz) [20] 200 First FFT window (power of sin) [3] 0 First forward FFT version [3] may need to make 1 or 2 First FFT storage time (s) [20] 4 First FFT amplitude [1] Enable second FFT [0] First backward FFT version [0] First backward FFT att. N [6] Second FFT bandwidth factor in powers of 2 [2] Second FFT window (power of sin) [0] Second forward FFT version [0] Second forward FFT att. N [7] Second FFT storage time (s) [5] Enable AFC/SPUR/DECODE [1] 0 AFC lock range Hz [500] AFC max drift Hz/minute [1000] Enable morse decoding [0] Max no of spurs to cancel [0] Spur timeconstant (0.1sek) [5] First mixer bandwidth reduction in powers of 2 [1] First mixer no of channels [1] Baseband storage time (s) [200] Output delay margin (0.1sek) [5] Output sampling speed (Hz) [6000] Default output mode [1] Audio expander exponent [3] A/D speed [22050] Check [1110038] You can carefully make a par_test file for mode "F", or make a par_wcw file maybe for mode "A", etc. That may get you started. If the files aren't made just right, they will not work. For starters, cut the A/D speed, or reduce the powers of sine, and/or broaden the FFT bin size, and/or turn off AFC to reduce CPU requirements. I am sure others will give you better information in this regard. I've always had fast computer and so haven't really learned what must be changed to speed things up. 3. Did you really try EVERY combination of parameters on the page? If not it would be helpful to know what you did try so we can figure out where things are wrong. And then there is always the possibility that the error has nothing to do with anything I said, but that it is a symptom of an audio driver or other problem. I hope there is something helpful in the above. 73, Roger Rehr W3SZ FN20ah 2 Merrymount Road Reading, PA 19609-1718 http://www.qsl.net/w3sz > -----Original Message----- > From: owner-linrad@xxxxxxxxxxxxxxxxxxxxx > [http://ham.te.hik.se/homepage/sm5bsz/linuxdsp/fft1time/fft1time.htm > > > > This is what Leif got with a 650 MHz Pentium III: > > > > SM 5 BSZ - First FFT timing for a large system using Pentium III > > (Coppermine) at 650MHz > > (Dec 30 2000) > > > -------------------------------------------------------------- > ---------- > > -------- > > Sampling rate = 96kHz. > > No of A/D channels = 4. > > No of RF channels = 2. > > Useful bandwidth 2 x 90 kHz. > > > > > > > > SIZE = 32768 16 bit no window, bandwidth 1.46Hz > > Vers Name Time > > 0 Radix 2 DIF C 37.15% > > 1 Radix 2 DIF ASM 34.95% > > 2 Twin Radix 2 ASM 41.75% > > 3 Radix 4 DIT C 33.92% > > 4 Twin radix 4 DIT C 33.10% > > 5 Twin radix 4 DIT SIMD 26.10% > > > > Typical operation > > SIZE = 8192 32 bit sin squared window, bandwidth 23Hz > > Vers Name Time > > 0 Radix 2 DIF C 24.01% > > 1 Radix 2 DIF ASM 22.06% > > 2 Twin Radix 2 ASM 20.17% > > 3 Radix 4 DIT C 22.87% > > 4 Twin radix 4 DIT C 19.70% > > 5 Twin radix 4 DIT SIMD 14.70% > > > > ------------------------------------- > > > > > > If we can all see all of your parameters, maybe we can help. > > > > 73, > > > > Roger Rehr > > W3SZ FN20ah > > 2 Merrymount Road > > Reading, PA 19609-1718 > > http://www.qsl.net/w3sz > > > > > > > > > -----Original Message----- > > > From: owner-linrad@xxxxxxxxxxxxxxxxxxxxx > > > [