Hi,
I have an aml-s905x-cc currently running Debian 12 with Linux 6.1.92. The network latency and ping response time is generally poor. I know it is a 100Mbps port however my really slow Raspberry Pi Model B can more than perform twice as well in respect to latency on its 100Mbps port.
The ping latency is of the order 1.0ms to 1Gbps servers on my 1Gbps LAN whereas the RPiB manages 0.3 to 0.35ms.
The RPiB has a configuration “smsc95xx.turbo_mode=0” to improve the latency but I’ve not seen any way of reducing latency on the Le Potato board.
It means the slow and ancient RPiB is a far better GPS Stratum 1 reference than the allegedly much more performant Libre Computer board.
Anyone with any ideas or configurations for improving this?
From an AML-S805X-AC (same chip as AML-S905X-CC in a different package), to a gigabit device on the same switch. Never seen a generic kernel get 0.3ms.
debian-12-aml-s805x-ac:~$ ping debian-12-aml-a311d-cc -A -c 20
PING debian-12-aml-a311d-cc (192.168.12.173) 56(84) bytes of data.
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=1 ttl=64 time=0.740 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=2 ttl=64 time=0.687 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=3 ttl=64 time=0.679 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=4 ttl=64 time=0.671 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=5 ttl=64 time=0.674 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=6 ttl=64 time=0.486 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=7 ttl=64 time=0.695 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=8 ttl=64 time=0.512 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=9 ttl=64 time=0.677 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=10 ttl=64 time=0.686 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=11 ttl=64 time=0.683 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=12 ttl=64 time=0.664 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=13 ttl=64 time=0.414 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=14 ttl=64 time=0.678 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=15 ttl=64 time=0.667 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=16 ttl=64 time=0.665 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=17 ttl=64 time=0.678 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=18 ttl=64 time=0.682 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=19 ttl=64 time=0.678 ms
64 bytes from 192.168.12.173: icmp_seq=20 ttl=64 time=0.676 ms
--- debian-12-aml-a311d-cc ping statistics ---
20 packets transmitted, 20 received, 0% packet loss, time 49ms
rtt min/avg/max/mdev = 0.414/0.649/0.740/0.078 ms, ipg/ewma 2.590/0.661 ms
From gigabit to gigabit
debian-12-aml-s905d3-cc:~$ ping debian-12-aml-a311d-cc -A -c 20
PING debian-12-aml-a311d-cc.lan (192.168.12.173) 56(84) bytes of data.
64 bytes from debian-12-aml-a311d-cc.lan (192.168.12.173): icmp_seq=1 ttl=64 time=0.736 ms
64 bytes from debian-12-aml-a311d-cc.lan (192.168.12.173): icmp_seq=2 ttl=64 time=0.669 ms
64 bytes from debian-12-aml-a311d-cc.lan (192.168.12.173): icmp_seq=3 ttl=64 time=0.683 ms
64 bytes from debian-12-aml-a311d-cc.lan (192.168.12.173): icmp_seq=4 ttl=64 time=0.627 ms
64 bytes from debian-12-aml-a311d-cc.lan (192.168.12.173): icmp_seq=5 ttl=64 time=0.634 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=6 ttl=64 time=0.519 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=7 ttl=64 time=0.402 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=8 ttl=64 time=0.619 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=9 ttl=64 time=0.620 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=10 ttl=64 time=0.608 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=11 ttl=64 time=0.603 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=12 ttl=64 time=0.598 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=13 ttl=64 time=0.608 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=14 ttl=64 time=0.598 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=15 ttl=64 time=0.611 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=16 ttl=64 time=0.615 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=17 ttl=64 time=0.604 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=18 ttl=64 time=0.616 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=19 ttl=64 time=0.474 ms
64 bytes from debian-12-aml-a311d-cc (192.168.12.173): icmp_seq=20 ttl=64 time=0.611 ms
--- debian-12-aml-a311d-cc.lan ping statistics ---
20 packets transmitted, 20 received, 0% packet loss, time 88ms
rtt min/avg/max/mdev = 0.402/0.602/0.736/0.068 ms, ipg/ewma 4.655/0.600 ms
There’s a few important things that affect network latency and trade off throughput. CPU frequency, packet offloading, DMA, interrupt handling. But getting 0.75ms is typical. As you’ve stated, your gigabit only gets 1.0ms.