Hacker News Reader

Comment by fxtentacle | Hacker News Reader

If I remember correctly, the IEEE 802.3an line coding overhead is around 2.6ms for each time you switch between SPF+ and RJ-45. That's in line with my measurements.

SPF+ switch to OM3 fiber to SPF+ PCIe card => 0.2ms

SPF+ switch to RJ-45 cable to RJ-45 PCIe card => around 3ms

View on HN

NAS-[10GbE]->switch-[1GbE]->asus router, 2 hops ping test: ``` yatli@yatao-nas ~ % ping 192.168.50.1 PING 192.168.50.1 (192.168.50.1) 56(84) bytes of data. 64 bytes from 192.168.50.1: icmp_seq=1 ttl=64 time=0.236 ms 64 bytes from 192.168.50.1: icmp_seq=2 ttl=64 time=0.195 ms 64 bytes from 192.168.50.1: icmp_seq=3 ttl=64 time=0.300 ms 64 bytes from 192.168.50.1: icmp_seq=4 ttl=64 time=0.271 ms 64 bytes from 192.168.50.1: icmp_seq=5 ttl=64 time=0.153 ms 64 bytes from 192.168.50.1: icmp_seq=6 ttl=64 time=0.216 ms 64 bytes from 192.168.50.1: icmp_seq=7 ttl=64 time=0.300 ms 64 bytes from 192.168.50.1: icmp_seq=8 ttl=64 time=0.165 ms 64 bytes from 192.168.50.1: icmp_seq=9 ttl=64 time=0.163 ms 64 bytes from 192.168.50.1: icmp_seq=10 ttl=64 time=0.265 ms 64 bytes from 192.168.50.1: icmp_seq=11 ttl=64 time=0.174 ms 64 bytes from 192.168.50.1: icmp_seq=12 ttl=64 time=0.272 ms 64 bytes from 192.168.50.1: icmp_seq=13 ttl=64 time=0.397 ms 64 bytes from 192.168.50.1: icmp_seq=14 ttl=64 time=0.256 ms ^C --- 192.168.50.1 ping statistics --- 14 packets transmitted, 14 received, 0% packet loss, time 13168ms rtt min/avg/max/mdev = 0.153/0.240/0.397/0.065 ms ```

OK it seems mistake was to put a RJ-45 transceiver into an SPF port, if your direct RJ-45 line is so much faster.

Yeah I think so. There might also be better converter modules. Anyway, my setup is caused by an oversight of not burying light pipes into the floor. Otherwise I guess I'll go with SFP+ too. I'm using TP-Link TL-ST1005 which is the cheapest 10GbE switch out there and it cost like $150. Also RJ-45 adapters/switches run anecdotally hotter than SFP+ ones.

either that, or the equipment is in awe because you mixed up its acronym

pretty wild, considering my phone averages at 2.2ms ROUND trip time when pinging the router.

Reply on news.ycombinator.com