On Thu, Oct 13, 2005 at 12:35:50AM -0700, Eric Blossom wrote: > > > > I believe it was gnuradio-examples/python/usrp/benchmark_usb.py that > > triggered the problem here. > > That should be the right answer, but is not completely reliable. Since I don't have a Tx board, I couldn't run that test "as is". It tries to open the Tx board first. I'll do a little hacking on something and then see if I encounter the problem doing something similar with two Rx boards or opening the Rx board first.
> Try running test_usrp_standard_rx with different values of the > -D <decim> option. Start with -D 128, then try -D 64, -D 32, -D 16, -D 8. > > -D 128 500kS/sec 2MB/sec > -D 64 1MS/sec 4MB/sec > -D 32 2MS/sec 8MB/sec > -D 16 4MS/sec 16MB/sec > -D 8 8MS/sec 32MB/sec These tests show the apparent 4MB/s limit which Wulf has mentioned. There also seem to be something that is related to the 4MB points in the actual transfers. I have run tests with 3.9 MB transfers with no overruns and 4.0 MB transfers with exactly 1. I would also expect the noverruns to go up as -D goes down. Clues there. Just don't know what they mean yet. ./test_usrp_standard_rx -M 1 -D 128 xfered 1.05e+06 bytes in 0.523 seconds. 2.004e+06 bytes/sec. cpu time = 0.01027 noverruns = 0 ./test_usrp_standard_rx -M 1 -D 64 xfered 1.05e+06 bytes in 0.262 seconds. 4e+06 bytes/sec. cpu time = 0.009881 noverruns = 0 ./test_usrp_standard_rx -M 1 -D 32 xfered 1.05e+06 bytes in 0.257 seconds. 4.085e+06 bytes/sec. cpu time = 0.009734 noverruns = 1 ./test_usrp_standard_rx -M 1 -D 16 xfered 1.05e+06 bytes in 0.256 seconds. 4.09e+06 bytes/sec. cpu time = 0.009536 noverruns = 0 ./test_usrp_standard_rx -M 1 -D 8 xfered 1.05e+06 bytes in 0.256 seconds. 4.089e+06 bytes/sec. cpu time = 0.009741 noverruns = 0 ./test_usrp_standard_rx -M 4 -D 128 xfered 4.19e+06 bytes in 2.1 seconds. 2.001e+06 bytes/sec. cpu time = 0.03939 noverruns = 0 ./test_usrp_standard_rx -M 4 -D 64 xfered 4.19e+06 bytes in 1.05 seconds. 4e+06 bytes/sec. cpu time = 0.03998 noverruns = 0 ./test_usrp_standard_rx -M 4 -D 32 xfered 4.19e+06 bytes in 1.03 seconds. 4.09e+06 bytes/sec. cpu time = 0.0389 noverruns = 5 ./test_usrp_standard_rx -M 4 -D 16 xfered 4.19e+06 bytes in 1.04 seconds. 4.042e+06 bytes/sec. cpu time = 0.03856 noverruns = 2 ./test_usrp_standard_rx -M 4 -D 8 xfered 4.19e+06 bytes in 1.02 seconds. 4.094e+06 bytes/sec. cpu time = 0.03855 noverruns = 1 ./test_usrp_standard_rx -M 16 -D 128 xfered 1.68e+07 bytes in 8.4 seconds. 1.998e+06 bytes/sec. cpu time = 0.1549 noverruns = 1 ./test_usrp_standard_rx -M 16 -D 64 xfered 1.68e+07 bytes in 4.19 seconds. 4e+06 bytes/sec. cpu time = 0.1501 noverruns = 0 ./test_usrp_standard_rx -M 16 -D 32 xfered 1.68e+07 bytes in 4.11 seconds. 4.078e+06 bytes/sec. cpu time = 0.152 noverruns = 20 ./test_usrp_standard_rx -M 16 -D 16 xfered 1.68e+07 bytes in 4.1 seconds. 4.094e+06 bytes/sec. cpu time = 0.155 noverruns = 10 ./test_usrp_standard_rx -M 16 -D 8 xfered 1.68e+07 bytes in 4.1 seconds. 4.095e+06 bytes/sec. cpu time = 0.1483 noverruns = 5 > Likewise, try test_usrp_standard_tx with different values of the > -I <interp> option. Start with -I 256, then try -I 128, 64, 32, 16. Can't, no Tx board. -- LRK [EMAIL PROTECTED] _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
