Hi Josh, Would you happen to suggest any more setting changes I could try before just deciding I need to depend on the older libusrp/gnuradio for recording 4 channels to disk from a USRP? Thanks, - Tom
________________________________ From: Josh Blum <j...@ettus.com> To: Tom Hendrick <sdtom...@yahoo.com> Cc: "discuss-gnuradio@gnu.org" <discuss-gnuradio@gnu.org> Sent: Saturday, March 2, 2013 9:18 AM Subject: Re: [Discuss-gnuradio] LibUSRP vs LibUHD Performance on older machines On 03/01/2013 05:16 PM, Tom Hendrick wrote: > Josh, > > Thank you so much for the suggestion. I will try this. I have 4GB of > ram and a 4GB swapfile size. Do you recommend any particular setting > for set_max_output_buffer(long max_output_buffer)? > > Make it 10s of megabytes, see if it helps. > Should I leave tb.run() as is, or modify the number of n_output_items > in conjunction with the I think that part of the API is deprecated (the argument to run). There is a similar call on top block, but Im recommending just the usrp source block. > > void set_max_output_buffer(long max_output_buffer)? > > > Also, do you recommend any particular settings using uhd_usrp_probe > --args="serial=123456, recv_frame_size=XXXX,num_recv_frames=XXXX", > send_frame_size=XXXX,send_recv_frames=XXX" > > > or should I leave it default? The custom 4 channel usrp block in the > older gnuradio version had the fusb_block and fusb_nblocks both set > to 512*32 > Go with the default while trying the above. -josh > Thanks, -Tom > > > > > ________________________________ From: Josh Blum <j...@ettus.com> To: > discuss-gnuradio@gnu.org Sent: Friday, March 1, 2013 2:55 PM Subject: > Re: [Discuss-gnuradio] LibUSRP vs LibUHD Performance on older > machines > > > > On 03/01/2013 04:51 PM, Tom Hendrick wrote: >> Hello all, >> >> I've had trouble making a 4 channel USRP samples at 1Ms/s write to >> file at 500 kS/s with ubuntu 12.04 and libuhd. I am getting >> several overruns and I had tried adjusting some of the parameters >> using usrd_probe_devices but with no success. I have a laptop with >> a duo core centrino processor which should be enough. >> >> I've made this 4 channel work successfully with the same exact >> laptop and with ubuntu 10.04 and the older version of gnuradio that >> uses libusrp. I get no underruns at all even for an entire hour of >> writing to file. >> >> >> Has anyone else experienced performance differences between libusrp >> and libuhd? I just want to make sure it isn't a configuration >> problem or something I'm doing wrong causing the overruns. If its >> likely an issue with libuhd, I guess I will just keep a backup of >> ubuntu 10.04 and gnuradio libusrp version installation files and >> leave my dual boot setup intact. >> >> Thank you very much, - Tom >> >> > > You might try setting a very large output buffer on the usrp source > block. I heard this helps (you should be able to call this in python > after the block constructs): > > /*! * \brief Sets max buffer size on all output ports. */ void > set_max_output_buffer(long max_output_buffer) > > -josh > >> >> _______________________________________________ Discuss-gnuradio >> mailing list Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > > _______________________________________________ Discuss-gnuradio > mailing list Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >
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