Hi
I’m wondering if anyone else has seen this: the board can receive UDP packets at a respectable rate (800Mbps+) but sending data performs poorly. With 1472 byte packets, netperf reports less than 200 Mbps, and netperf uses 100% of CPU.
$ netperf -4 -l 60 -t UDP_STREAM -H 192.168.7.16 -- -m 1472
MIGRATED UDP STREAM TEST from 0.0.0.0 () port 0 AF_INET to 192.168.7.16 () port 0 AF_INET : demo
Socket Message Elapsed Messages
Size Size Time Okay Errors Throughput
bytes bytes secs # # 10^6bits/sec
212992 1472 60.00 903491 0 177.32
212992 60.00 903491 177.32
If my maths is right, that’s only about 15000 packets per second (and the bandwidth scales with packet size, so it seems to be a per-packet-overhead issue rather than a bandwidth issue). My laptop can sustain 40x that - I expect TX1 to be slower, but not that much slower, and the asymmetry seems particularly odd (normally my experience is that receive is harder than send).
The CPUs are at max clock using the script provided in the main TX1 thread:
$ for i in 0 1 2 3 ; do echo "CPU${i}: `cat /sys/devices/system/cpu/cpu$i/cpufreq/scaling_cur_freq`"; done
CPU0: 1912500
CPU1: 1912500
CPU2: 1912500
CPU3: 1912500
If I do a TCP test with a large message size, performance is good, presumably because the NIC is doing TCP segmentation offload.