can you see if this is the same when you have an idle window? on our prod env, (10Ge,) iperf still shows pretty high bandwidth... ------------------------------------------------------------ Client connecting to lonfs23, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 3] local 10.21.16.70 port 45573 connected with 10.21.16.69 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.0 sec 10.5 GBytes 8.98 Gbits/sec On Feb 16, 2011, at 11:00 AM, Roland Rabben wrote: > iperf on the production environment shows on average about 350-400 > Mbps throughput. Luis E. Cerezo http://www.luiscerezo.org http://twitter.com/luiscerezo http://flickr.com/photos/luiscerezo Voice: 412 223 7396