> > > > > > > > I have half a dozen D-Link System Inc DGE-530T Gigabit Ethernet > > Adapter (rev 11) running in standard PCs (32bit Intel) with Redhat > > Server and F8, Fast Ethernet or GBit depending on the switches (no > > VLAN or fancy stuff). No problem there. > > We've pretty much standardized on Intel or Broadcom cards. The drivers > are pretty bulletproof and they support all the bizarro stuff like > jumbo frames, QoS, VLAN (802.1q), trunking and the like. > Slightly OT but ... Having install one of my 2 DGE-530Ts I am trying to talk to a machine with a built in GBit NIC based on the Broadcom 5789 chip. It works perfectly with mtu 1500 - different performance depending which iperf is a "server" naxos has DGE-530T fuerte has built in BCM5789 [root@fuerte net]# iperf -c naxos ------------------------------------------------------------ Client connecting to naxos, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 3] local 148.197.29.246 port 57748 connected with 148.197.29.242 port 5001 [ 3] 0.0-10.0 sec 420 MBytes 352 Mbits/sec ------------------------------------- ------------------------------------- [root@naxos ~]# iperf -c fuerte ------------------------------------------------------------ Client connecting to fuerte, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 3] local 148.197.29.242 port 38347 connected with 148.197.29.246 port 5001 [ 3] 0.0-10.0 sec 705 MBytes 591 Mbits/sec ####################################################################### lspci 02:00.0 Ethernet controller: Broadcom Corporation NetLink BCM5789 Gigabit Ethernet PCI Express (rev 21) ------------------------------------- This is a fully updated F8 machine and the "NIC" uses [root@fuerte ~]# ethtool -i eth0 driver: tg3 version: 3.81 firmware-version: 5789-v3.29a bus-info: 0000:02:00.0 ------------------------- The built in BCM5789 fails to set the mtu greater than 1500 !!!!!!!! (The DGE-530T will set mtu 9000 OK) [root@fuerte ~]# ifconfig eth0 mtu 9000 SIOCSIFMTU: Invalid argument ------------------------------------- [root@fuerte ~]# ifconfig eth0 mtu 1499 [root@fuerte ~]# ifconfig eth0 mtu 1501 SIOCSIFMTU: Invalid argument [root@fuerte ~]# ifconfig eth0 mtu 1500 [root@fuerte ~]# ------------------------------------- I have down loaded the kernel src and had a look at the tg3 driver /root/rpmbuild/BUILD/kernel-2.6.23/linux-2.6.23.x86_64/drivers/net/tg3.c /* hardware minimum and maximum for a single frame's data payload */ #define TG3_MIN_MTU 60 #define TG3_MAX_MTU(tp) \ ((tp->tg3_flags2 & TG3_FLG2_JUMBO_CAPABLE) ? 9000 : 1500) I have been to the Broadcom site and down loaded the latest driver tg3-3.81c-1.src.rpm and the tar version tg3-3.81c.tar.gz I have failed miserably to rpmbuild or make either version !! I can give full details if someone can help. So what am I asking ????? 1. Is the performance as expected ? 2. Is faster one way than the other normal when using iperf ? 3. Is it possible that even though the chip supports jumbo frames the implementation on the board does not ? 4. Is using jumbo frames worth the effort ? My next move is to install a 2nd DGE-530T on fuerte Then I can justify hijacking the thread !!!! John