On 07/05/2010 12:33 PM, Josh Blum wrote: > I can think of a nicer way to print the error messages SX, but dropped > packets are a fact of life; especially running at 25 Msps. > > On my linux box, running benchmark at full rate, i usually see a few > dropped packets initially and at the end when it finishes. > > AMD Athlon(tm) II X4 620 Processor > Realtek Semiconductor Co., Ltd. RTL-8169 Gigabit Ethernet (rev 10) > > I see dropped packets at much lower bandwidths, but with more complex flow-graphs. But the puzzling thing is the CPU isn't even close to 100% when I see these.
On my 6-core Phenom II X6 1090T with 8G of 1333 DDR3 with the CPUs hard-configured to run at 3.2GHz, I can run usrp2_fft.py at 25Msps, and get the occasional dropped packet, but I can't run more-complex flow-graphs beyond about 8Msps without it getting into serious droppage, even without 100% CPU utilization. This is with an RTL ethernet chip on the mobo. I've been told that Intel e1000e cards do somewhat better-- perhaps deeper FIFOs or something like that. I know that for the project I just left, I was doing a device driver for a Xilinx-TEMAC with a proprietary buffer manager in the FPGA--it had a FIFO depth of only 8, which caused a lot of heartache for bursts of closely-spaced packets, and a USRP2 runnning "full bore" would almost certainly have caused it really bad heartburn :-) -- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
