Chris- > I'm using the USRP/DBSRX to record data for GPS. GPS tracking demands a > continuous stream of data -- dropped bits make tracking impossible. > 4Msps of complex data supplies 16 MB/s -- within USB2 bandwidth and my 4 > disk RAID0 bandwidth. > > I record the data using my own c++ version of cfile. I never get an > error or overrun condition from usrp_standard::read so it appears that > everything is working fine. However, when I process the data it is > clear that data is dropped -- approximately a few thousand samples every > minute or two. I typically record data for one hour at a time. > > I read data from the USRP in batches of 8192 16 bit short samples. > > Anyone have any tips on tracking down why I am dropping data?
Is there a way for you to temporarily take file-write out of the equation? I.e. can your code look at the bitstream and know if it remains continuous / intact? The "every minute or two" thing makes me suspicious that some HDD related thing is going on. 16 MBbyte/sec is around 1 GByte/minute. -Jeff _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
