Josh Blum-3 wrote: > > >>- dont use a throttle, the usrp sink *is* back-pressuring the stream > >>- use this new signal source on my new_blocks or next branch, its much >>much faster: > >>git://gnuradio.org/jblum.git > >>http://gnuradio.org/cgit/jblum.git/tree/gr-blocks/lib/signal_source.cc?h=new_blocks > > Didn't realize that a throttle was unnecessary with the usrp. Thanks for > pointing that out. I see that you have a lot of other blocks in your > repository as well. Do these have any advantage to the ones included with > gnuradio? > > > >>50 Msps is serious amount of data to push through your computer. More >>than a feeling, even the most serious computers can easily have a >>bottleneck. I suspect that the gnuradio core signal source cannot >>sustain 50Msps in 1 thread/1 work function. > > Makes sense. I would assume that, as long as I'm using grc at least, I'm > limited to one thread? > >>Why do you think you cant change the wire format? It sounds like you >>changed it to sc8 format (above). > Should have worded that more carefully. I can choose 8 or 16 bits over the > wire. My thinking was that I might be able to increase the rate of > decimation (on second thought, decimation has more to do with sampling > frequency than a data bottleneck) and also decrease the precision and use > an integer less than 8bits. Basically, I thought ethernet may have been > the bottleneck. Decreasing precision shouldn't be necessary, I'm just > trying to build an understanding here. > >>I prototyping whatever it is you are trying to do at a lower rate, then >>optimizing it in SIMD routines to get up to 50 Msps on the host. > I was totally unaware of SIMD before you mentioned it. That's an > interesting subject. It is my understand that SIMD is integrated into > gnuradio through VOLK as of Dec. 2010. Doesn't look like I can use VOLK > directely from grc, or even from Python. Looks like it needs to be > implemented at the block level in C++. Is this the case? > >>Also, try examples/tx_waveforms with --otw=sc8 --rate=50e6 and >>experiment with that so you can see if your PC can sustain the rate with >>minimal load. > > I actually couldn't find that in my /usr/local/share/gnuradio/examples > folder. Do I need to download it elsewhere? > Thanks for the informative post Josh! 50MSPS will probably prove unnecessary for the project that I'm working on. I was worried that perhaps I was doing something fundamentally wrong and that's why I wasn't getting the full sampling rate out of this device. -- View this message in context: http://old.nabble.com/Cannot-Achieve-50MSPS-Sampling-Rate-tp33444517p33447202.html Sent from the GnuRadio mailing list archive at Nabble.com.
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