iperf3 and Chelsio T6225-CR

I ran four tests yesterday using iperf3. The T6225-CR NIC still runs with Chelsio’s SM10G-SR optics. It’s amazing that receiving TCP streams runs at full speed. Sending TCP streams limps away only at a few megabits per second. This wasn’t expected at all. Even IPv6 runs faster than IPv4 for these particular tests. The Cisco switch at the other end uses Fiberworks’ SFP-10G-SR optics. Does anyone have any clues? Continue reading iperf3 and Chelsio T6225-CR

Chelsio T6225-CR and TOE

After upgrading to a recent base/stable/11, I noticed ifconfig -m now displays two more bits:

cc0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
             options=ec07bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,          VLAN_HWTSO,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
        capabilities=ecc7bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,TOE4,TOE6,VLAN_HWTSO,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
        ether 00:07:43:XX:XX:X0
        hwaddr 00:07:43:XX:XX:X0
        nd6 options=8021<PERFORMNUD,AUTO_LINKLOCAL,DEFAULTIF>
        media: Ethernet 10Gbase-SR <full-duplex,rxpause,txpause>
        status: active
        supported media:
                media 10Gbase-SR mediaopt full-duplex,rxpause,txpause
                media 10Gbase-SR mediaopt full-duplex,rxpause
                media 10Gbase-SR mediaopt full-duplex,txpause
                media 10Gbase-SR mediaopt full-duplex
                media 1000baseSX mediaopt full-duplex,rxpause,txpause
                media 1000baseSX mediaopt full-duplex,rxpause
                media 1000baseSX mediaopt full-duplex,txpause
                media 1000baseSX mediaopt full-duplex

TOE4 and TOE6 appear in the capabilities word, but not in the options word. (TOE in this case being TCP Offload Engine.) Continue reading Chelsio T6225-CR and TOE